CN115244903B

CN115244903B - Method and apparatus for transmitting and receiving PDCCH in wireless communication system

Info

Publication number: CN115244903B
Application number: CN202180020029.4A
Authority: CN
Inventors: 金圭奭; 金亨泰; 姜智源
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2020-03-10
Filing date: 2021-03-09
Publication date: 2024-04-19
Anticipated expiration: 2041-03-09
Also published as: US11895650B2; KR20220133912A; WO2021182837A1; JP2023517951A; US11864179B2; US20230096196A1; EP4120642A1; CN115244903A; EP4120642A4; US20230126866A1; KR102544819B1

Abstract

A method and apparatus for transmitting and receiving a Physical Downlink Control Channel (PDCCH) in a wireless communication system are disclosed. A method for receiving a PDCCH according to an embodiment of the present disclosure may include the steps of: receiving configuration information related to a control resource set (CORESET) from a base station; and receiving the PDCCH from the base station within CORESET. The configuration information may include Transmission Control Indicator (TCI) state information related to CORESET, the TCI state information may include information on one or more reference signals in quasi co-located (QCL) relation with one or more antenna ports of a demodulation reference signal (DMRS) of the PDCCH, and a plurality of TCI states may be configured for CORESET.

Description

Method and apparatus for transmitting and receiving PDCCH in wireless communication system

Technical Field

The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting and receiving a Physical Downlink Control Channel (PDCCH) in a wireless communication system.

Background

A mobile communication system has been developed to provide a voice service while guaranteeing mobility of a user. However, the mobile communication system has been extended to data traffic as well as voice traffic, and currently, explosive growth of traffic has resulted in resource shortage, and users have demanded faster services, and thus, more advanced mobile communication systems have been demanded.

The general need for the next generation mobile communication system should be able to support the accommodation of explosive data traffic, a significant increase in transmission rate per user, the accommodation of a significantly increased number of connected devices, very low end-to-end delay and energy efficiency. For this reason, various technologies of dual connectivity, massive multiple input multiple output (massive MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), ultra wideband support, device networking, etc. have been studied.

Disclosure of Invention

Technical problem

Technical object of the present disclosure is to provide a method and apparatus for transmitting and receiving a Physical Downlink Control Channel (PDCCH).

Further, another technical object of the present disclosure is to provide a method and apparatus for transmitting and receiving a Physical Downlink Control Channel (PDCCH) based on a Single Frequency Network (SFN).

Technical objects achieved by the present disclosure are not limited to the above technical objects, and other technical objects not described herein will be clearly understood from the following description by those skilled in the relevant art.

Technical proposal

A method of receiving a Physical Downlink Control Channel (PDCCH) in a wireless communication system according to aspects of the present disclosure may include: receiving configuration information related to a control resource set (CORESET) from a base station; and receiving CORESET the PDCCH from the base station. The configuration information may include Transmission Control Indicator (TCI) state information related to CORESET, the TCI state information may include information on one or more reference signals having a quasi co-located (QCL) relationship with one or more antenna ports of a demodulation reference signal (DMRS) of the PDCCH, and the plurality of TCI states may be configured for CORESET.

A terminal for receiving a Physical Downlink Control Channel (PDCCH) in a wireless communication system according to additional aspects of the present disclosure may include: at least one transceiver for transmitting and receiving radio signals; and at least one processor for controlling the at least one transceiver. The at least one processor may be configured to: receiving CORESET of the PDCCH from the base station; and receiving CORESET the PDCCH from the base station. The configuration information may include Transmission Control Indicator (TCI) state information related to CORESET, the TCI state information may include information on one or more reference signals having a quasi co-located (QCL) relationship with one or more antenna ports of a demodulation reference signal (DMRS) of the PDCCH, and configure a plurality of TCI states for CORESET.

At least one non-transitory computer-readable medium storing at least one instruction in accordance with additional aspects of the present disclosure may control an apparatus for receiving a Physical Downlink Control Channel (PDCCH) to: receiving configuration information related to a control resource set (CORESET) from a base station; and receiving CORESET the PDCCH from the base station. The configuration information may include Transmission Control Indicator (TCI) state information related to CORESET, the TCI state information may include information on one or more reference signals having a quasi co-located (QCL) relationship with one or more antenna ports of a demodulation reference signal (DMRS) of the PDCCH, and configure a plurality of TCI states for CORESET.

A processing apparatus configured to control a terminal to receive a Physical Downlink Control Channel (PDCCH) in a wireless communication system may include: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that perform operations based upon execution by the at least one processor. The operations may include: receiving configuration information related to a control resource set (CORESET) from a base station; and receiving CORESET the PDCCH from the base station. The configuration information may include Transmission Control Indicator (TCI) state information related to CORESET, the TCI state information may include information on one or more reference signals having a quasi co-located (QCL) relationship with one or more antenna ports of a demodulation reference signal (DMRS) of the PDCCH, and configure a plurality of TCI states for CORESET.

A method of transmitting a Physical Downlink Control Channel (PDCCH) in a wireless communication system according to additional aspects of the present disclosure may include: transmitting configuration information related to the control resource set (CORESET) to the terminal; and transmitting the PDCCH in CORESET to the terminal. The configuration information may include Transmission Control Indicator (TCI) state information related to CORESET, the TCI state information may include information on one or more reference signals having a quasi co-located (QCL) relationship with one or more antenna ports of a demodulation reference signal (DMRS) of the PDCCH, and the plurality of TCI states may be configured for CORESET.

A base station for transmitting a Physical Downlink Control Channel (PDCCH) in a wireless communication system according to additional aspects of the present disclosure may include: at least one transceiver for transmitting and receiving radio signals; and at least one processor for controlling the at least one transceiver. The at least one processor is configured to: transmitting configuration information related to the control resource set (CORESET) to the terminal; and transmitting the PDCCH in CORESET to the terminal. The configuration information may include Transmission Control Indicator (TCI) state information related to CORESET, the TCI state information may include information on one or more reference signals having a quasi co-located (QCL) relationship with one or more antenna ports of a demodulation reference signal (DMRS) of the PDCCH, and the plurality of TCI states may be configured for CORESET.

Advantageous effects

According to embodiments of the present disclosure, reliability for downlink control information transmission and reception may be improved by transmitting and receiving a PDCCH using an SFN technology.

In addition, according to embodiments of the present disclosure, channel estimation performance may be improved by performing channel estimation/compensation based on different reference signals for PDCCHs transmitted/received using an SFN technique.

In addition, according to the embodiments of the present disclosure, by performing channel estimation/compensation on PDCCHs transmitted/received using an SFN technique based on different reference signals, the complexity of a terminal UE is not increased to obtain high estimation performance.

The effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein can be clearly understood by those skilled in the art from the following description.

Drawings

The accompanying drawings, which are included to provide a further understanding of the detailed description of the disclosure, provide examples of the disclosure and describe features of the disclosure through the detailed description.

Fig. 1 illustrates a structure of a wireless communication system to which the present disclosure can be applied.

Fig. 2 illustrates a frame structure in a wireless communication system to which the present disclosure may be applied.

Fig. 3 illustrates a resource grid in a wireless communication system to which the present disclosure may be applied.

Fig. 4 illustrates physical resource blocks in a wireless communication system to which the present disclosure may be applied.

Fig. 5 illustrates a slot structure in a wireless communication system to which the present disclosure may be applied.

Fig. 6 illustrates a physical channel used in a wireless communication system to which the present disclosure can be applied and general signal transmission and reception methods using the physical channel.

Fig. 7 illustrates a method of multiple TRP transmissions in a wireless communication system to which the present disclosure may be applied.

Fig. 8 is a diagram illustrating channel characteristics of an SFN channel model in a wireless communication system to which the present disclosure may be applied.

Fig. 9 illustrates a method of configuring whether to operate an SFN according to an embodiment of the present disclosure.

Fig. 10 illustrates a method of configuring whether to operate an SFN according to an embodiment of the present disclosure.

Fig. 11 illustrates a MAC Control Element (CE) configuring a specific TCI state in CORESET in a wireless communication system to which the present disclosure may be applied.

Fig. 12 illustrates methods defined in different MLs according to embodiments of the present disclosure.

Fig. 13 illustrates MAC control elements for indicating multiple TCI states according to an embodiment of the disclosure.

Fig. 14 illustrates a MAC control element for indicating activation/deactivation of an additional TCI state according to an embodiment of the present disclosure.

Fig. 15 is a diagram illustrating DMRS antenna port-to-layer mapping according to an embodiment of the present disclosure.

Fig. 16 is a diagram illustrating DMRS antenna port-to-layer mapping according to an embodiment of the present disclosure.

Fig. 17 to 19 are diagrams for explaining a repeated transmission operation according to an embodiment of the present disclosure.

Fig. 20 and 21 are diagrams for explaining a repeated transmission operation according to an embodiment of the present disclosure.

Fig. 22 illustrates a signaling procedure between a terminal and a network according to an embodiment of the present disclosure.

Fig. 23 is a diagram illustrating an operation of a terminal of a method for receiving a PDCCH according to an embodiment of the present disclosure.

Fig. 24 is a diagram illustrating an operation of a base station of a method for transmitting a PDCCH according to an embodiment of the present disclosure.

Fig. 25 illustrates a block diagram of a wireless communication device according to an embodiment of the present disclosure.

Fig. 26 illustrates a vehicle apparatus according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description, which is disclosed by the accompanying drawings, is intended to describe exemplary embodiments of the disclosure and is not intended to represent the only embodiments in which the disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the relevant art that the present disclosure may be practiced without these specific details.

In some cases, known structures and devices may be omitted or may be shown in block diagram form based on core functions of each structure and device in order to prevent ambiguity of the concepts of the present disclosure.

In this disclosure, when an element is referred to as being "connected," "combined," or "linked" to another element, it can comprise the indirect connection and the direct connection of yet another element therebetween. Furthermore, in the present disclosure, the terms "comprises" and/or "comprising" specify the presence of stated features, steps, operations, components, and/or elements, but do not preclude the presence or addition of one or more other features, stages, operations, components, elements, and/or groups thereof.

In the present invention, terms such as "first," "second," and the like are used merely to distinguish one element from another element and are not used to limit the order or importance between the elements unless otherwise indicated. Thus, within the scope of the present disclosure, a first element in an embodiment may be referred to as a second element in another embodiment, and as such, a second element in an embodiment may be referred to as a first element in another embodiment.

The terminology used in the present disclosure is for the purpose of describing particular embodiments, and is not intended to limit the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "and/or" as used in this disclosure may refer to one of the relevant listed items or to any and all possible combinations of two or more of them. Furthermore, unless otherwise indicated, the words "/" and/or "between words in the present invention have the same meaning.

The present disclosure describes a wireless communication network or a wireless communication system, and operations performed in the wireless communication network may be performed in a process in which a device (e.g., a base station) controlling the corresponding wireless communication network controls the network and transmits or receives signals, or may be performed in a process in which signals are transmitted or received between a terminal associated to the corresponding wireless network and the network or terminal.

In the present disclosure, a transmission or reception channel includes a meaning of transmitting or receiving information or signals through a corresponding channel. For example, transmitting a control channel means transmitting control information or a control signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a data signal through the data channel.

Hereinafter, downlink (DL) means communication from a base station to a terminal, and Uplink (UL) means communication from a terminal to a base station. In the downlink, the transmitter may be part of a base station and the receiver may be part of a terminal. In the uplink, the transmitter may be part of a terminal and the receiver may be part of a base station. The base station may be expressed as a first communication device and the terminal may be expressed as a second communication device. A Base Station (BS) may be replaced with terms such as a fixed station, a node B, eNB (evolved node B), a gNB (next generation node B), a BTS (base transceiver system), an Access Point (AP), a network (5G network), an AI (artificial intelligence) system/module, an RSU (road side unit), a robot, an unmanned aerial vehicle (UAV: unmanned aerial vehicle), an AR (augmented reality) device, a VR (virtual reality) device, and the like. In addition, the terminal may be fixed or mobile, and may be replaced with terms of UE (user equipment), MS (mobile station), UT (user terminal), MSs (mobile subscriber station), SS (subscriber station), AMS (advanced mobile station), WT (wireless terminal), MTC (machine type communication) device, M2M (machine to machine) device, D2D (device to device) device, vehicle, RSU (roadside unit), robot, AI (artificial intelligence) module, unmanned aerial vehicle (UAV: unmanned aerial vehicle), AR (augmented reality) device, VR (virtual reality) device, or the like.

The following description may be used for various radio access systems, such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may be implemented by e.g. UTRA (universal terrestrial radio access) or CDMA 2000. TDMA may be implemented by radio technologies such as GSM (global system for mobile communications)/GPRS (general packet radio service)/EDGE (data rate enhanced GSM evolution). OFDMA may be implemented by radio technologies such as IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), and the like. UTRA is part of UMTS (universal mobile telecommunications system). The 3GPP (third Generation partnership project) LTE (Long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA, and LTE-A (advanced)/LTE-A pro is a release-advanced version of 3GPP LTE. The 3GPP NR (New radio or New radio Access technology) is an advanced release of 3GPP LTE/LTE-A/LTE-A pro.

For the sake of clarity of description, description is made based on a 3GPP communication system (e.g., LTE-A, NR), but the technical ideas of the present disclosure are not limited thereto. LTE means technology after 3GPP TS (technical specification) 36.Xxx release 8. Specifically, the LTE technology in or after 3gpp TS 36.xxx release 10 is referred to as LTE-a, and the LTE technology in or after 3gpp TS 36.xxx release 13 is referred to as LTE-a pro.3GPP NR means technology in or after TS 38.Xxx release 15. LTE/NR may be referred to as a 3GPP system. "xxx" means the detailed number of a standard file. LTE/NR may be generally referred to as a 3GPP system. For background art, terms, abbreviations, etc. used to describe the present disclosure, reference may be made to matters described in the standard documents disclosed before the present disclosure. For example, the following documents may be referred to.

For 3GPP LTE, reference may be made to TS 36.211 (physical channel and modulation), TS 36.212 (multiplexing and channel coding), TS 36.213 (physical layer procedure), TS 36.300 (general description), TS 36.331 (radio resource control).

For 3GPP NR, reference may be made to TS 38.211 (physical channel and modulation), TS 38.212 (multiplexing and channel coding), TS 38.213 (physical layer procedure for control), TS 38.214 (physical layer procedure for data), TS 38.300 (NR and NG-RAN (new generation radio access network) overall description), TS 38.331 (radio resource control protocol specification).

Abbreviations for terms that may be used in the present disclosure are defined as follows.

-BM: beam management

-CQI: channel quality indicator

-CRI: channel state information-reference signal resource indicator

-CSI: channel state information

CSI-IM: channel state information-interference measurement

-CSI-RS: channel state information-reference signal

-DMRS: demodulation reference signal

-FDM: frequency division multiplexing

-FFT: fast fourier transform

IFDMA: interleaved frequency division multiple access

-IFFT: inverse fast fourier transform

-L1-RSRP: layer 1 reference signal received power

-L1-RSRQ: layer 1 reference signal reception quality

-MAC: media access control

-NZP: non-zero power

-OFDM: orthogonal frequency division multiplexing

PDCCH: physical downlink control channel

PDSCH: physical downlink shared channel

-PMI: precoding matrix indicator

-RE: resource elements

RI: rank indicator

-RRC: radio resource control

-RSSI: received signal strength indicator

-Rx: reception of

-QCL: quasi co-located

SINR: signal to interference noise ratio

SSB (or SS/PBCH block): synchronization signal block (including PSS (primary synchronization signal), SSS (secondary synchronization signal) and PBCH (physical broadcast channel))

-TDM: time division multiplexing

-TRP: transmitting and receiving points

-TRS: tracking reference signals

-Tx: transmitting

-UE: user equipment

-ZP: zero power

Integrated system

As more communication devices require higher capacity, a need has arisen for improved mobile broadband communications compared to existing Radio Access Technologies (RATs). In addition, large-scale MTC (machine type communication) that provides various services anytime and anywhere by connecting a plurality of devices and things is also one of the main problems to be considered for next-generation communication. In addition, communication system designs that consider reliability and latency sensitive services/terminals are discussed. Thus, the introduction of next generation RATs considering eMBB (enhanced mobile broadband communications), mMTC (large-scale MTC), URLLC (ultra-reliable low-latency communications), etc. is discussed, and for convenience, the corresponding technology is referred to as NR in this disclosure. NR is an expression representing an example of a 5G RAT.

A new RAT system including NR uses an OFDM transmission method or a transmission method similar thereto. The new RAT system may follow different OFDM parameters than those of LTE. Alternatively, the new RAT system follows the parameters of the existing LTE/LTE-a as it is, but may support a wider system bandwidth (e.g., 100 MHz). Alternatively, one cell may support multiple parameter sets. In other words, terminals operating according to different parameter sets may coexist in one cell.

The parameter set corresponds to one subcarrier spacing in the frequency domain. As the reference subcarrier spacing is scaled by an integer N, different parameter sets may be defined.

Referring to fig. 1, NG-RAN is configured with a gNB providing a control plane (RRC) protocol side for NG-RA (NG radio access) user plane (i.e., new AS (access layer) sublayer/PDCP (packet data convergence protocol)/RLC (radio link control)/MAC/PHY) and UE. The gNB is interconnected by an Xn interface. Furthermore, the gNB is connected to the NGC (new generation core) through an NG interface. More specifically, the gNB is connected to an AMF (access and mobility management power) through an N2 interface, and to a UPF (user plane function) through an N3 interface.

The NR system can support multiple parameter sets. Here, the parameter set may be defined by a subcarrier spacing and a Cyclic Prefix (CP) overhead. Here, the plurality of subcarrier spacings may be derived by scaling the basic (reference) subcarrier spacing by an integer N (or μ). Furthermore, although it is assumed that a very low subcarrier spacing is not used in a very high carrier frequency, the parameter set used may be selected independently of the frequency band. Further, various frame structures according to a plurality of parameter sets may be supported in the NR system.

Hereinafter, OFDM parameter sets and frame structures that can be considered in an NR system will be described. The plurality of OFDM parameter sets supported in the NR system may be defined as table 1 below.

TABLE 1

The NR supports a plurality of parameter sets (or subcarrier spacing (SCS)) for supporting various 5G services. For example, when SCS is 15kHz, supporting wide area of traditional cellular band; and when SCS is 30kHz/60kHz, supporting dense city, lower time delay and wider carrier bandwidth; and when SCS is 60kHz or higher, bandwidths exceeding 24.25GHz are supported to overcome phase noise. The NR frequency band is defined as the frequency range of both types (FR 1, FR 2). FR1 and FR2 can be configured as shown in table 2 below. In addition, FR2 may mean millimeter wave (mmW).

TABLE 2

Regarding the frame structure in the NR system, the sizes of various fields in the time domain are expressed as multiples of T _c＝1/(Δf_max·N_f) time units. Here, Δf _max i is 480·10 ³ Hz, and N _f is 4096. The downlink and uplink transmissions are configured (organized) as radio frames having a duration of T _f＝1/(Δf_maxN_f/100)·T_c =10 ms. Here, the radio frame is configured with 10 subframes each having a duration of T _sf＝(Δf_maxN_f/1000)·T_c. In this case, there may be one frame set for the uplink and one frame set for the downlink. Furthermore, transmissions in the i-th uplink frame from the terminal should start earlier than the corresponding downlink frame in the corresponding terminal by T _TA＝(N_TA+N_TA,offset)T_c. For a subcarrier spacing configuration μ, the slots are numbered in ascending order of n _s ^μ∈{0,...,N_slot ^subframe,μ -1 in the subframe and in ascending order of n _s,f ^μ∈{0,...,N_slot ^frame,μ -1 in the radio frame. One slot is configured with N _symb ^slot consecutive OFDM symbols, and N _symb ^slot is determined according to the CP. The beginning of slot n _s ^μ in a subframe is aligned in time with the beginning of OFDM symbol n _s ^μN_symb ^slot in the same subframe. All terminals may not perform transmission and reception at the same time, which means that all OFDM symbols of a downlink slot or an uplink slot may not be used. Table 3 shows the number of OFDM symbols per slot (N _symb ^slot), the number of slots per radio frame (N _slot ^frame,μ), and the number of slots per subframe (N _slot ^subframe,μ) in the normal CP, and table 4 shows the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in the extended CP.

TABLE 3

μ	N_symb ^slot	N_slot ^frame,μ	N_slot ^subframe,μ
				0	14	10	1
1	14	20	2
				2	14	40	4
3	14	80	8
				4	14	160	16

TABLE 4

μ	N_symb ^slot	N_slot ^frame,μ	N_slot ^subframe,μ
				2	12	40	4

Fig. 2 is an example of μ=2 (SCS is 60 kHz), and referring to table 3,1 subframe may include 4 slots. 1 subframe = {1,2,4} as shown in fig. 2 is an example, and the number of slots that can be included in 1 subframe is defined as in table 3 or table 4. In addition, the micro slot may include 2,4, or 7 symbols or more or less. Regarding physical resources in the NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. may be considered. Hereinafter, physical resources that can be considered in the NR system will be described in detail.

First, with respect to antenna ports, antenna ports are defined such that channels carrying symbols in an antenna port can be inferred from channels carrying other symbols in the same antenna port. When the massive nature of the channel in which the symbols in one antenna port are carried can be inferred from the channel carrying the symbols of another antenna port, it can be said that 2 antenna ports are in QC/QCL (quasi co-located or quasi co-located) relationship. In this case, the large-scale property includes at least one of delay spread, doppler spread, frequency shift, average received power, and reception timing.

Referring to fig. 3, it is illustratively described that a resource grid is configured with N _RB ^μN_sc ^RB subcarriers in a frequency domain and one subframe is configured with 14·2 ^μ OFDM symbols, but is not limited thereto. In an NR system, a transmitted signal is described by 2 ^μN_symb ^(μ) OFDM symbols and one or more resource grids configured with N _RB ^μN_sc ^RB subcarriers. Here, N _RB ^μ≤N_RB ^max,μ.N_RB ^max,μ denotes a maximum transmission bandwidth, which may be different between uplink and downlink and between parameter sets. In this case, one resource grid may be configured per mu and antenna port p. Each element of the resource grid for μ and antenna port p is called a resource element and is uniquely identified by an index pair (k, l'). Here, k=0,..n _RB ^μN_sc ^RB -1 is an index in the frequency domain, and l' =0,..2 ^μN_symb ^(μ) -1 refers to a symbol position in a subframe. When referencing a resource element in a slot, an index pair (k, l) is used. Here, l=0,..n _symb ^μ -1. The resource elements (k, l') for μ and antenna port p correspond to complex values a _k,l' ^(p,μ). When there is no risk of confusion or when no particular antenna port or parameter set is specified, the indices p and μmay be discarded, and the complex value may then be a _k,l' ^(p) or a _k,l'. Further, a Resource Block (RB) is defined to N _sc ^RB =12 consecutive subcarriers in the frequency domain.

Point a functions as a common reference point for the resource block grid and is obtained as follows.

OffsetToPointA for the primary cell (PCell) downlink denotes the frequency offset between point a and the lowest subcarrier of the lowest resource block overlapping with the SS/PBCH block used by the terminal for initial cell selection. It is assumed that a subcarrier spacing of 15kHz is used for FR1 and a subcarrier spacing of 60kHz is used for FR2, which is expressed in units of resource blocks.

-AbsoluteFrequencyPointA denotes the frequency position of point a, expressed in ARFCN (absolute radio frequency channel number).

For a subcarrier spacing configuration μ, the common resource blocks are numbered from 0 up in the frequency domain. The center of subcarrier 0 of common resource block 0 for subcarrier spacing configuration μ is the same as in "point a". The relationship between the common resource block number n _CRB ^μ of the subcarrier spacing configuration μ in the frequency domain and the resource elements (k, l) is given as in the following equation 1.

[ 1]

In equation 1, k is defined with respect to point a such that k=0 corresponds to a subcarrier centered on point a. The physical resource blocks are numbered from 0 to N _BWP,i ^size,μ -1 in the bandwidth part (BWP) and i is the number of BWP. The relationship between the physical resource block n _PRB and the common resource block n _CRB in BWP i is given by the following equation 2.

[ 2]

N _BWP,i ^start,μ is the common resource block from which BWP starts with respect to common resource block 0.

Fig. 4 illustrates physical resource blocks in a wireless communication system to which the present disclosure may be applied. Also, fig. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.

Referring to fig. 4 and 5, a slot includes a plurality of symbols in the time domain. For example, for a normal CP,1 slot includes 7 symbols, but for an extended CP,1 slot includes 6 symbols.

The carrier comprises a plurality of subcarriers in the frequency domain. An RB (resource block) is defined to be a plurality (e.g., 12) of consecutive subcarriers in the frequency domain. BWP (bandwidth part) is defined as a plurality of consecutive (physical) resource blocks in the frequency domain and may correspond to one parameter set (e.g., SCS, CP length, etc.). The carrier may include a maximum of N (e.g., 5) BWPs. Data communication may be performed through the activated BWP, and only one BWP may be activated for one terminal. In a resource grid, each element is referred to as a Resource Element (RE) and may map one complex symbol.

In an NR system, each Component Carrier (CC) may support up to 400MHz. If a terminal operating in such a wideband CC is always operated to turn on a radio Frequency (FR) chip for the entire CC, terminal battery consumption may increase. Alternatively, when considering a plurality of application cases operating in one wideband CC (e.g., eMBB, URLLC, mmtc, V X, etc.), different parameter sets (e.g., subcarrier spacing, etc.) may be supported in each of the frequency bands in the corresponding CC. Alternatively, each terminal may have different capabilities for maximum bandwidth. In view of this, the base station may instruct the terminal to operate in only a partial bandwidth, not in the full bandwidth of the wideband CC, and for convenience, the corresponding partial bandwidth is defined as a bandwidth part (BWP). BWP may be configured with consecutive RBs on the frequency axis and may correspond to one parameter set (e.g., subcarrier spacing, CP length, time slot/micro-slot duration).

Meanwhile, the base station may configure a plurality of BWP even in one CC configured for the terminal. For example, BWP occupying a relatively small frequency domain may be configured in a PDCCH monitoring slot, and PDSCH indicated by PDCCH may be scheduled in a larger BWP. Alternatively, when the UE is congested in a specific BWP, some terminals may be configured with other BWPs for load balancing. Alternatively, some full-bandwidth intermediate spectrum may be excluded in consideration of frequency domain inter-cell interference cancellation between neighboring cells, etc., and BWP on both edges may be configured in the same slot. In other words, the base station may configure at least one DL/UL BWP to a terminal associated with the wideband CC. The base station may activate at least one DL/UL BWP of the configured DL/UL BWP at a specific time (through L1 signaling or MAC CE (control element) or RRC signaling, etc.). Further, the base station may instruct (through L1 signaling or MAC CE or RRC signaling, etc.) to switch to other configured DL/UL BWP. Alternatively, based on a timer, when the timer value expires, a switch may be made to the determined DL/UL BWP. Here, the activated DL/UL BWP is defined as an active DL/UL BWP. But may not receive the configuration on the DL/UL BWP before the terminal performs the initial access procedure or sets up the RRC connection, so the DL/UL BWP assumed by the terminal in these cases is defined as the initially active DL/UL BWP.

In a wireless communication system, a terminal receives information from a base station through a downlink and transmits information to the base station through an uplink. The information transmitted and received by the base station and the terminal includes data and various control information, and there are various physical channels according to the type/purpose of the information they transmit and receive.

When the terminal is turned on or newly enters a cell, it performs an initial cell search including synchronization with a base station, etc. (S601). For initial cell search, a terminal may synchronize with a base station by receiving a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) from the base station and obtain information such as a cell Identifier (ID). The terminal may then acquire broadcast information in the cell by receiving a Physical Broadcast Channel (PBCH) from the base station. Meanwhile, the terminal may check a downlink channel state by receiving a downlink reference signal (DL RS) in an initial cell search phase.

The terminal that completed the initial cell search may obtain more detailed system information by receiving a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH) according to information carried in the PDCCH (S602).

Meanwhile, when the terminal accesses the base station for the first time or does not have radio resources for signal transmission, it may perform a Random Access (RACH) procedure on the base station (S603 to S606). For the random access procedure, the terminal may transmit a specific sequence as a preamble through a Physical Random Access Channel (PRACH) (S603 and S605), and may receive a response message to the preamble through a PDCCH and a corresponding PDSCH (S604 and S606). The contention-based RACH may additionally perform a contention resolution procedure.

The terminal that then performs the above procedure may perform PDCCH/PDSCH reception (S607) and PUSCH (physical uplink shared channel)/PUCCH (physical uplink control channel) transmission (S608) as a general uplink/downlink signal transmission procedure. Specifically, the terminal receives Downlink Control Information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for a terminal, and a format varies according to its purpose of use.

Meanwhile, control information transmitted by the terminal to the base station through the uplink or received by the terminal from the base station includes downlink/uplink ACK/NACK (acknowledgement/non-acknowledgement) signals, CQI (channel order indicator), PMI (precoding matrix indicator), RI (rank indicator), and the like. For the 3GPP LTE system, the terminal can transmit the control information of CQI/PMI/RI and the like through PUSCH and/or PUCCH.

Table 5 shows an example of DCI formats in an NR system.

TABLE 5

Referring to table 5, DCI formats 0_0, 0_1, and 0_2 may include resource information (e.g., UL/SUL (supplemental UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), information related to a Transport Block (TB) (e.g., MCS (modulation coding and scheme), NDI (new data indicator), RV (redundancy version), etc.), information related to HARQ (hybrid-automatic repeat and request) (e.g., procedure number, DAI (downlink assignment index), PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information related to scheduling of PUSCH (e.g., PUSCH power control, etc.), and control information included in each DCI format may be predefined. DCI format 0_0 is used to schedule PUSCH in one cell. The information included in the DCI format 0_0 is CRC (cyclic redundancy check) scrambled by a C-RNTI (cell radio network temporary identifier) or CS-RNTI (configured scheduling RNTI) or MCS-C-RNTI (modulation coding scheme cell RNTI) and is transmitted.

DCI format 0_1 is used to indicate scheduling of one or more PUSCHs or Configuring Grant (CG) downlink feedback information to terminals in one cell. The information included in the DCI format 0_1 is scrambled by a C-RNTI or CS-RNTI or SP-CSI-RNTI (semi-persistent CSI RNTI) or MCS-C-RNTI and transmitted.

DCI format 0_2 is used to schedule PUSCH in one cell. The information included in the DCI format 0_2 is scrambled by a C-RNTI or CS-RNTI or SP-CSI-RNTI or MCS-C-RNTI and transmitted.

Next, DCI formats 1_0, 1_1, and 1_2 may include resource information (e.g., frequency resource allocation, time resource allocation, VRB (virtual resource block) -PRB (physical resource block) mapping, etc.), information related to a Transport Block (TB) (e.g., MCS, NDI, RV, etc.), information related to HARQ (e.g., a process number, DAI, PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., antenna ports, TCI (transmission configuration indicator), SRS (sounding reference signal) request, etc.), information related to a PUCCH related to scheduling of PDSCH (e.g., PUCCH power control, PUCCH resource indicator, etc.), and control information included in each DCI format may be predefined.

DCI format 1_0 is used to schedule PDSCH in one DL cell. The information included in the DCI format 1_0 is a CRC scrambled and transmitted by a C-RNTI or CS-RNTI or MCS-C-RNTI.

DCI format 1_1 is used to schedule PDSCH in one cell. The information included in the DCI format 1_1 is a CRC scrambled and transmitted by a C-RNTI or CS-RNTI or MCS-C-RNTI.

DCI format 1_2 is used to schedule PDSCH in one cell. The information contained in DCI format 1_2 is a CRC scrambled and transmitted by C-RNTI or CS-RNTI or MCS-C-RNTI.

Quasi co-location (QCL)

The antenna ports are defined such that the channel transmitting a symbol in an antenna port can be inferred from the channels transmitting other symbols in the same antenna port. When the properties of the channel carrying the symbols of one antenna port can be inferred from the channel carrying the symbols of another antenna port, it can be said that 2 antenna ports are in QC/QCL (quasi co-located or quasi co-located) relationship.

Here, the channel properties include at least one of delay spread, doppler spread, frequency/doppler shift, average received power, receive timing/average delay, or spatial RX parameters. Here, the spatial Rx parameter means a spatial (Rx) channel attribute parameter such as an angle of arrival.

The terminal may be configured in a list of up to M TCI-State configurations in the higher layer parameters PDSCH-Config to decode PDSCH according to detected PDCCH with the corresponding terminal and the expected DCI for the given serving cell. M depends on UE capability.

Each TCI-State includes parameters for configuring a quasi co-sited relationship between ports of one or two DL reference signals and DM-RSs of PDSCH.

The quasi co-sited relationship is configured by higher layer parameters qcl-Type1 for the first DL RS and qcl-Type2 (if configured) for the second DL RS. For both DL RSs, the QCL type is different, whether the reference is the same DL RS or different DL RSs.

The quasi-co-location Type corresponding to each DL RS is given by the higher layer parameter QCL-Type of QCL-Info and may take one of the following values.

- "Qcl-TypeA": { Doppler shift, doppler spread, average delay, delay spread }

- "Qcl-TypeB": { Doppler shift, doppler spread }

- "Qcl-TypeC": { Doppler shift, average delay }

- "Qcl-TypeD": { spatial Rx parameters })

For example, when the target antenna port is a particular NZP CSI-RS, the corresponding NZP CSI-RS antenna port may be indicated/configured to be co-located with a particular TRS quasi-with respect to qcl-TypeA and with a particular SSB quasi-with respect to qcl-TypeD. A terminal receiving such an indication/configuration may receive the corresponding NZP CSI-RS by using doppler, measure a delay value in qcl-TypeA TRS and apply an Rx beam for reception qcl-TypeD SSB to the reception of the corresponding NZP CSI-RS.

The UE may receive an activation command through MAC CE signaling for mapping up to 8 TCI states to a code point of the DCI field "transmission configuration indication".

Transport Block (TB) size determination

When higher layer parameter maxNrofCodeWordsScheduledByDCI indicates that two codeword transmissions are enabled, if for the respective TB, I _MCS = 1 and rv _id = 1, then one of the two TBs is disabled by DCI format 1_1. If two TBs are enabled, TBs 1 and 2 are mapped to codewords 0 and 1, respectively. If only one TB is enabled, the enabled TB is always mapped to the first codeword.

For PDSCH allocated by DCI format 1_0, format 1_1, or format 1_2 with CRC scrambled by C-RNTI (cell RNTI), MCS-C-RNTI (modulation coding scheme cell RNTI), TC-RNTI (temporary cell RNTI), CS-RNTI (configured scheduling RNTI), or SI-RNTI (system information RNTI), the UE may first determine a TB Size (TBs) as follows except when a TB is disabled in DCI format 1_1.

1) The UE first determines the number of REs in the slot (N _RE).

-The UE first determines the number of REs allocated for PDSCH in a Physical Resource Block (PRB) by N '_RE＝N_sc ^RB·N_symb ^sh-N_DMRS ^PRB-N_oh ^PRB (N' _RE). Here, N _sc ^RB =12 is the number of subcarriers in the PRB, N _symb ^sh is the number of symbols allocated for the PDSCH in the slot, N _DMRS ^PRB is the number of REs for the DM-RS per PRB in the scheduling duration including the overhead of the DM-RS CDM group without data, as indicated by DCI format 1_1 or format 1_2 or as described by DCI format 1_0, and N _oh ^PRB is the overhead configured by higher layer parameters xOverhead in the PDSCH-ServingCellConfig. If xOverhead in PDSCH-ServingCellconfig (a value within 0, 6,12, or 18) is not configured, then N _oh ^PRB is set to 0. When PDSCH is scheduled by PDCCH with CRC scrambled by SI-RNTI, RA-RNTI (random access RNTI), msgB-RNTI or P-RNTI (paging RNTI), N _oh ^PRB is assumed to be 0.

-The UE determines the total number of REs allocated for PDSCH by N _RE＝min(156,N'_RE)·n_PRB (N _RE). Here, n _PRB is the total number of PRBs allocated to the UE.

2) Unquantized intermediate variables (N _info) were obtained by N _info＝N_RE·R·Q_m. V.

If N _info is less than or equal to 3824, then step 3 is used as the next step in TBS determination.

Otherwise, step 4 is used as the next step for TBS determination.

3) If N _info is less than or equal to 3824, the TBS is determined as follows.

-Intermediate number of quantization of information bits N' _info＝max(24,2ⁿ·floor(N_info/2ⁿ)), where n=max (3, floor (log ₂(N_info)) -6.

Using table 6 below, find the nearest TBS not less than N' _info.

Table 6 illustrates the TBS in the case of N _info.ltoreq.3824.

TABLE 6

/>

4) If N _info >3824, the TBS is determined as follows.

-The quantized intermediate number N' _info＝max(3840,2ⁿ×round((N_info-24)/2ⁿ of information bits)), where n=floor (log ₂(N_info -24)) -5, and the balance point in the round function is decomposed into the next largest integer (i.e. when the nearest number is 2, a larger number is output).

If R.ltoreq.1/4,

Tbs=8·c·ceiling ((N '_info +24)/(8·c)) -24, where c=ceiling ((N' _info +24)/3816),

Otherwise the first set of parameters is selected,

If N' _info >8424,

Tbs=8·c·ceiling ((N '_info +24)/(8·c)) -24, where c=ceiling ((N' _info +24)/8424),

Otherwise, tbs=8·ceiling ((N' _info +24)/8) -24

If 28.ltoreq.I _MCS.ltoreq.31,

Assume that the TBS is determined from DCI transmitted from the last PDCCH of the same TB using 0.ltoreq.I _MCS.ltoreq.27. If there is no PDCCH using the same TB of 0.ltoreq.I _MCS.ltoreq.27, and if the highest PDSCH for the same TB is semi-persistently scheduled, a TBS is determined from the most recent semi-persistently scheduled assignment PDCCH.

Otherwise the first set of parameters is selected,

-Assuming that the TBs is determined from DCI sent in the last PDCCH of the same TB using 0- _MCS -28. If there is no PDCCH using the same TB of 0.ltoreq.I _MCS.ltoreq.28, and if the highest PDSCH for the same TB is semi-persistently scheduled, a TBS is determined from the most recent semi-persistently scheduled allocation PDCCH.

The UE does not expect to receive PDSCH allocated by PDCCH with CRC scrambled by SI-RNTI with TBS greater than 2976 bits.

When two TCI states are indicated in the code point of the DCI field "transmission configuration indication" and when a DM-RS port in one CDM group is indicated in the DCI field "antenna port" and when FDMSchemeB is configured for the UE, TBS determination follows steps 1 to 4 described above, where step 1 is modified as follows: the UE determines a total number of REs allocated to the PDSCH through N _RE＝min(156,N'_RE)·n_PRB (N _RE), where N _PRB is a total number of allocated PRBs corresponding to the first TCI state. Further, the determined TBS of the PDSCH transmission occasion associated with the first TCI state also applies to the PDSCH transmission occasion associated with the second TCI state.

When two TCI states are indicated in the code point of the DCI field "transmission configuration indication" and when a DM-RS port in one CDM group is indicated in the DCI field "antenna port" and when TDMSCHEMEA is configured for the UE, TBS determination follows steps 1 to 4 described above, where step 1 is modified as follows: the UE determines the number of REs allocated to PDSCH in the PRB (N '_RE) through N' _RE＝N_sc ^RB·N_symb ^sh-N_DMRS ^PRB-N_oh ^PRB, where N _symb ^sh is the number of symbols allocated by PDSCH in the slot corresponding to the first TCI state. And, the determined TBS of the PDSCH transmission occasion associated with the first TCI state is also applied to the PDSCH transmission occasion associated with the second TCI state.

Operation related to multiple TRP

A coordinated multipoint (CoMP) scheme refers to a scheme in which a plurality of base stations effectively control interference by exchanging (e.g., using an X2 interface) or using channel information (e.g., RI/CQI/PMI/LI (layer indicator), etc.) fed back by a terminal and cooperatively transmitting to the terminal. CoMP can be classified into Joint Transmission (JT), coordinated Scheduling (CS), coordinated Beamforming (CB), dynamic Point Selection (DPS), dynamic Point Blocking (DPB), etc., according to the scheme used.

The M-TRP transmission scheme in which M TRPs transmit data to one terminal can be mainly classified into i) eMBB M-TRP transmission scheme for increasing a transmission rate, and ii) URLLC M-TRP transmission scheme for increasing a reception success rate and reducing a delay.

Further, regarding DCI transmission, M-TRP transmission schemes may be classified into i) M-TRP transmission based on M-DCI (multiple DCIs), where each TRP transmits a different DCI, and ii) M-TRP transmission based on S-DCI (single DCI), where one TRP transmits a DCI. For example, for S-DCI based M-TRP transmission, all scheduling information on data transmitted by M TRPs should be delivered to a terminal by one DCI, which may be used in the context of an ideal backhaul (ideal BH) where dynamic cooperation between two TRPs is possible.

For TDM-based URLLC M-TRP transmission, scheme 3/4 is being discussed for standardization. Specifically, scheme 4 refers to a scheme in which one TRP transmits a Transport Block (TB) in one slot, and has an effect of improving probability of data reception by the same TB received from a plurality of TRPs in a plurality of slots. Meanwhile, scheme 3 refers to a scheme in which one TRP transmits TBs through a consecutive number of OFDM symbols (i.e., symbol groups), and the TRP may be configured to transmit the same TBs through different symbol groups in one slot.

In addition, the UE may recognize PUSCH (or PUCCH) scheduled by DCI received in a different control resource set (CORESET) (or CORESET belonging to a different CORESET group) as PUSCH (or PUCCH) transmitted to a different TRP, or may recognize PDSCH (or PDCCH) from a different TRP. In addition, the method for UL transmission (e.g., PUSCH/PUCCH) transmitted to different TRPs described below may be equivalently applied to UL transmission (e.g., PUSCH/PUCCH) transmitted to different panels belonging to the same TRP.

Further, MTRP-URLLC may refer to M TRPs transmitting the same Transport Block (TB) by using different layers/times/frequencies. The UE configured with the MTRP-URLLC transmission scheme receives indications on a plurality of TCI states through DCI, and may assume that data received through QCL RS using each TCI state is the same TB. On the other hand, MTRP-eMBB may refer to M TRPs transmitting different TBs by using different layers/times/frequencies. The UE configured with the MTRP-eMBB transmission scheme receives indications on a plurality of TCI states through DCI, and may assume that data received through QCL RSs using each TCI state is a different TB. In this regard, since the UE classifies and uses the RNTI configured for MTRP-URLLC and the RNTI configured for MTRP-eMBB, respectively, it can decide/determine whether the corresponding M-TRP transmission is URLLC transmission or eMBB transmission. In other words, when the CRC masking of the DCI received by the UE is performed by using the RNTI configured for MTRP-URLLC, it may correspond to URLLC transmission, and when the CRC masking of the DCI is performed by using the RNTI configured for MTRP-eMBB, it may correspond to eMBB transmission.

Hereinafter, CORESET group IDs described/mentioned in the present disclosure may refer to index/identification information (e.g., ID, etc.) of CORESET for distinguishing for each TRP/panel. In addition, CORESET groups may be groups/union of CORESET that are distinguished by index/identification information (e.g., ID)/CORESET group ID, etc. for distinguishing CORESET for each TRP/panel. In an example, CORESET group IDs may be specific index information defined in the CORESET configuration. In this case, CORESET groups may be configured/indicated/defined by indexes defined in CORESET configuration for each CORESET. Additionally/alternatively, CORESET group IDs may refer to index/identification information/indicators or the like for distinguishing/identifying between CORESET associated with each TRP/panel configuration. Hereinafter, CORESET group IDs described/mentioned in the present disclosure may be represented by being replaced with specific index/specific identification information/specific indicator for distinguishing/identifying between CORESET associated with each TRP/panel configuration. The CORESET group IDs, i.e., specific indexes/specific identification information/specific indicators for distinguishing/identifying between CORESET associated with each TRP/panel configuration, may be configured/indicated to the terminal by higher layer signaling (e.g., RRC signaling)/L2 signaling (e.g., MAC-CE)/L1 signaling (e.g., DCI), etc. In an example, the configuration/indication may be such that PDCCH detection will be performed per TRP/panel (i.e., per TRP/panel belonging to the same CORESET group) in units of the corresponding CORESET groups. Additionally/alternatively, the configuration/indication may be such that uplink control information (e.g., CSI, HARQ-a/N (ACK/NACK), SR (scheduling request)) and/or uplink physical channel resources (e.g., PUCCH/PRACH/SRs resources) are separated and managed/controlled per TRP/panel (i.e., per TRP/panel belonging to the same CORESET group) in units of corresponding CORESET groups. Additionally/alternatively, HARQ a/N (processing/retransmission) for PDSCH/PUSCH and the like scheduled per TRP/panel may be managed per corresponding CORESET group (i.e., per TRP/panel belonging to the same CORESET group).

For example, higher layer parameters ControlResourceSet Information Element (IE) is used to configure a time/frequency control resource set (CORESET). In an example, the set of control resources (CORESET) may be related to the detection and reception of downlink control information. ControlResourceSet IE may include an ID associated with CORESET (e.g., controlResourceSetID)/index for CORESET pool of CORESET (e.g., CORESETPoolIndex)/CORESET/time/frequency resource configuration of TCI information associated with CORESET, etc. In an example, the index of the CORESET pool (e.g., CORESETPoolIndex) may be configured to be 0 or 1. In the description, CORESET groups may correspond to CORESET pools and CORESET group IDs may correspond to CORESET Chi Suoyin (e.g., CORESETPoolIndex).

NCJT (non-coherent joint transmission) is a scheme in which a plurality of Transmission Points (TPs) transmit data to one terminal by using the same time-frequency resource, and TPs transmit data between TPs using different DMRS (demodulation multiplexing reference signals) through different layers, i.e., through different DMRS ports.

The TP delivers the data scheduling information to the terminal receiving NCJT through DCI. Here, a scheme in which each TP participating NCJT delivers scheduling information on data transmitted by itself through DCI is referred to as "multi-DCI based NCJT". Since each of N TPs participating in NCJT transmissions transmits DL grant DCI and PDSCH to the UE, the UE receives N DCIs and N PDSCHs from the N TPs. Meanwhile, a scheme in which one representative TP delivers scheduling information on data transmitted by itself and data transmitted by different TPs (i.e., TPs participating in NCJT) through one DCI is referred to as "NCJT" based on a single DCI. Here, N TPs transmit one PDSCH, but each TP transmits only some of the layers included in one PDSCH. For example, when transmitting 4-layer data, TP 1 may transmit 2 layers to the UE, and TP 2 may transmit 2 remaining layers to the UE.

Hereinafter, the partially overlapped NCJT will be described.

In addition, NCJT can be classified into a fully overlapped NCJT in which time-frequency resources transmitted by each TP are fully overlapped and a partially overlapped NCJT in which only some of the time-frequency resources are overlapped. In other words, for partially overlapping NCJT, data for both TP 1 and TP 2 are transmitted in some time-frequency resources, and data for only one of TP 1 or TP 2 is transmitted in the remaining time-frequency resources.

Hereinafter, a method for improving reliability in the multi-TRP will be described.

As a transmission and reception method for improving reliability using transmission among a plurality of TRPs, the following two methods can be considered.

Fig. 7 illustrates a method of multi-TRP transmission in a wireless communication system to which the present disclosure may be applied.

Referring to fig. 7 (a), a case where groups of layers transmitting the same Codeword (CW)/Transport Block (TB) correspond to different TRPs is shown. Herein, a layer group may refer to a predetermined set of layers including one or more layers. In this case, there are the following advantages: the amount of transmission resources increases due to the number of layers, so that robust channel coding with a low coding rate can be used for TBs, and additionally, since a plurality of TRPs have different channels, it can be expected to improve the reliability of a received signal based on diversity gain.

Referring to fig. 7 (b), an example of transmitting different CWs through groups of layers corresponding to different TRPs is shown. Here, it can be assumed that TBs corresponding to cw#1 and cw#2 in the figures are identical to each other. In other words, cw#1 and cw#2 mean that the same TB is transformed from different TRPs to different CWs by channel coding or the like, respectively. Thus, it can be regarded as an example of repeatedly transmitting the same TB. In the case of fig. 7 (b), there is a disadvantage in that a code rate corresponding to TB is higher as compared with fig. 7 (a). However, there is an advantage in that the code rate can be adjusted by indicating a different RV (redundancy version) value, or the modulation order of each CW of coded bits generated by the same TB can be adjusted according to the channel environment.

According to the methods shown in fig. 7 (a) and 7 (b) above, the data reception probability of the terminal can be improved because the same TB is repeatedly transmitted through different groups of layers, and each group of layers is transmitted by a different TRP/panel. It is called an M-TRP URLLC transmission method based on SDM (space division multiplexing). Layers belonging to different layer groups are respectively transmitted through DMRS ports belonging to different DMRS CDM groups.

In addition, the above-described contents related to a plurality of TRPs are described based on an SDM (space division multiplexing) method using different layers, but it can naturally be extended and applied to an FDM (frequency division multiplexing) method based on different frequency domain resources (e.g., RB/PRB (set) etc.) and/or a TDM (time division multiplexing) method based on different time domain resources (e.g., slots, symbols, sub-symbols, etc.).

Signaling and operating method for high speed scenario (HST) -Single Frequency Network (SFN) deployment

In the process of 3GPP release 13, RAN4 research project (SI) for improving performance requirements in high speed scenarios (HST) was approved, and the results of SI are summarized in TR 36.878. In these results, TR 36.878 summarizes the actual high-speed scenarios from the operator for cellular service support, and where the future scenarios with higher priority are as follows.

SFN (single frequency network) scenario: an RRH (remote radio head) or RAU (remote antenna unit) is deployed through an optical fiber in a tunnel environment. The RRHs or RAUs share the same cell Identifier (ID). The repeater is not installed on a train (train).

Cable scenario of a crack in a tunnel (from a broken cable to a repeater): the broken cable is used to spread the signal through the tunnel environment. The repeater is mounted on the train and signals within the train via the broken cable.

The HST channel model is designed to analyze high speed scenarios and wherein the channel model for SFN is specified as follows.

The channel model designed for a Single Frequency Network (SFN) scenario is a two-tap time-varying channel model and is characterized by a doppler shift, tap delay, relative power given for each tap.

In the case of the HST-SFN deployed channel model, channels from two different Remote Radio Heads (RRHs) are defined as two different taps. And each channel includes different doppler shift, relative power and tap delay values.

For a terminal, signals transmitted from different RRHs can be received in a combined form, and a great performance degradation may occur for a specific duration due to channel characteristics. For example, when a terminal passes through a midpoint between two RRHs, the two channels have very similar sizes and have large doppler shift values of different codes. In this case, if the terminal does not sufficiently compensate for the different doppler shifts, significant performance degradation may occur. To compensate for this problem, in existing LTE systems, the network informs the terminal that it is SFN operation. In addition, after the terminal assumes that there are different Doppler shifts, different Doppler shift values can be estimated and compensated for. However, in this method, the performance may vary greatly depending on the estimation capability/accuracy of the terminal capable of estimating a plurality of doppler shift values from the combined signal. In addition, it may have the following drawbacks: for high performance, the complexity of the terminal increases. The present disclosure proposes a method that can compensate for these drawbacks.

In the present disclosure, for convenience of description, it is assumed that two TRPs (e.g., TRP1/TRP 2) operate. However, this assumption does not limit the technical scope of the present disclosure.

It is apparent that what is described as TRP in this disclosure may be for ease of description, which may also be construed in terms such as panel/beam.

In this specification, L1 (layer 1) signaling may refer to DCI-based dynamic signaling between a base station and a terminal, and L2 (layer 2) signaling may refer to RRC/MAC CE (control element) -based higher layer signaling between the base station and the terminal.

Proposal #1: method for configuring different QCL reference signals in the same DMRS port

The current standard defines higher layer parameters called "TCI-State" for configuring QCL Reference Signals (RSs) of PDSCH/PDCCH, and the definition of TCI-State is shown in table 7 below.

TABLE 7

As can be seen from Table 7, one TCI-State may include a total of two QCL RSs, such as QCL-Type1/QCL-Type2. Here, in the case of qcl-Type1, one Type of Type a/Type b/Type c may be configured, and in qcl-Type2, typeD may be configured. Since TypeD refers to the RS (i.e., spatial Rx parameters) for the reception beam of the terminal, one of channel information capable of acquiring such as doppler shift/doppler spread/average delay/delay spread can be configured for each TCI-State. Meanwhile, through the discussion of Rel-16 multi-TRP transmission, each code point in a "TCI (transmission configuration indication)" field for indicating a TCI state in DCI has been improved to correspond to a single TCI state or two TCI states. The following protocol shows these enhancements.

The TCI indication framework should be modified at least in Rel-16 for eMBB.

Each TCI code point in the DCI may correspond to one or two TCI states.

When two TCI states are activated in one TCI code point, each TCI state corresponds to one CDM group for at least DMRS type 1.

In a TCI state configuration of one or two TCI states available for each TCI code point, an enhancement of the MAC CE for mapping one or two TCI states for one TCI code point.

When two TCI states are indicated by TCI code points, for DMRS type 1 and type 2 for eMBB, if the indicated DMRS ports are in two CDM groups,

The first TCI state is applied to the first indicated CDM group and the second TCI state is applied to the second indicated CDM group.

-When two TCI states are indicated by one TCI code point, for DMRS type 1 and type 2 for eMBB and URLLC scheme-1 a, the first TCI state corresponds to the CDM group of the first antenna port indicated by the antenna port indication table if the indicated DMRS ports are in two CDM groups.

Hereinafter, a method of defining TCI-state as a higher layer parameter and/or a method for improving performance in HST-SFN deployment based on the definition of TCI field in DCI will be presented.

Proposal a#1: when different TCI state(s) are indicated to the terminal through the TCI field in the DCI, the terminal may assume that the indicated DMRS port(s) are configured with SFN based on the multiple TCI states, and may perform channel estimation/compensation based on QCL RSs corresponding to the different TCI states.

In the case of proposal a#1, different TCI states may be indicated for the same DMRS port(s). However, since the terminal may not be able to distinguish between the multi-TRP transmission operation and the SFN operation defined in Rel-16 only by the above definition, the terminal may distinguish between the Rel-16 multi-TRP transmission operation and the SFN operation based on additional conditions described later.

Proposal a#1-1: the base station may configure whether to perform SFN operation based on L2 signaling for a particular (or all or each) code point of the TCI field in the DCI. Here, i) when different TCI states are indicated to the terminal through a specific code point of a TCI field in the DCI, and ii) a specific (or all or each) code point is configured with an SFN, the terminal may assume that the indicated DMRS port(s) is configured with an SFN, and may perform channel estimation/compensation based on QCL RSs corresponding to the different TCI states.

In the current standard, a 3-bit TCI field may be defined in DCI. In this case, whether to perform SFN operation may be configured for a total of 8 code points defined as 3 bits. Table 8 below shows an example of the TCI field defining the proposed method.

Table 8 illustrates a TCI field configuring whether to perform SFN operation.

TABLE 8

Code point	TCI state	SFN
			000	{#1}	N/A
001	{#3}	N/A
			010	{#1,#3}	Opening device
011	{#2}	N/A
			100	{#4}	N/A
101	{#2,#4}	Switch for closing
			110	{#5}	N/A
111	{#6}	N/A

In table 8, in the column of the SFN, on indicates that the SFN operation is configured, and off indicates that the SFN operation is not configured.

In table 8, it can be seen that two different TCI states are configured at two codepoints 010 and 101. Here, in case of 010, it shows that SFN operation is configured, and in case of 101, it shows that SFN operation is not configured. Accordingly, when a code point corresponding to 010 is indicated to the terminal through the TCI field in the DCI, the terminal may perform channel estimation/compensation based on QCL RSs of TCI states corresponding to #1 and # 3. In this case, the terminal ignores the Rel-16 multi-TRP transmission operation and may be defined as operating as an SFN. On the other hand, when a code point corresponding to 101 is indicated to the terminal through the TCI field in the DCI, the terminal may perform PDSCH decoding based on the multi-TRP transmission operation defined in Rel-16.

In the present disclosure, assuming that a terminal has configured SFN operation, an example of a method of performing channel estimation/compensation based on QCL RSs of different TCI states is as follows. The terminal may continuously track channel information such as doppler shift/doppler spread/average delay/delay spread for each QCL RS in different TCI states. Thus, when the terminal assumes that SFN operation is configured for the same DMRS port(s) and indicates a plurality of TCI states, the terminal may perform channel compensation under the assumption that there are two different taps based on a channel value corresponding to the QCL RS of each TCI state. For details, refer to the method described in section 6.4.3.1 of TR 36.878. In this way, when the base station indicates whether to operate the SFN and the plurality of QCL RSs for the same DMRS port(s), since the terminal can estimate each channel value from RSs separated from each other without estimating different channel values (e.g., doppler shift) from the combined received signal, the complexity of the terminal can be reduced, and also the estimation performance for the channel corresponding to each RRH can be improved. Hereinafter, even though not separately described in the present disclosure, a channel estimation/compensation method for DMRS port(s) configured with SFN may follow the above-described method.

Proposal A#1-1-1: the base station may configure whether to perform SFN operation for a particular (or all or each) code point of the TCI field in the DCI. Here, the different TCI states may be indicated by specific code points of the TCI field in the DCI. In the case of a terminal configured with an SFN at a specific code point, whether or not to actually operate the SFN may be determined based on the number of CDM groups including DMRS port(s) indicated through DCI and/or QCL type configured in TCI state indicated through the specific code point.

In addition to the proposal A#1-1 described above, additional operating conditions may be considered. The method may be applied to dynamically indicate a particular transmission scheme relative to different transmission schemes.

Referring to fig. 9 (a), in the case of a 101 code point, it can be regarded as an example of multi-TRP transmission (defined in Rel-16). In this case, when the DMRS port(s) indicated by the DCI are included in different CDM groups, it may be interpreted as NCJT transmission. On the other hand, when the DMRS port(s) indicated by DCI is included in the same CDM group, it may be interpreted as one transmission method in FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA. Meanwhile, 010 code points may be examples of the proposed method of the present disclosure.

In case of A1 in fig. 9 (a), when DMRS port(s) indicated by DCI are included in different CDM groups, they are interpreted as SFNs, and when included in the same CDM group, they may be an example of one transmission method interpreted as FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA. On the other hand, in the case of A2 in fig. 9 (a), when the DMRS port(s) indicated by DCI are included in different CDM groups, they may be interpreted as NCJT, and when included in the same CDM group, they may be interpreted as SFN.

Fig. 9 (b) shows an example of determining whether to actually SFN operation based on the QCL type configured in the TCI state.

In the case of 010 code points in fig. 9 (b), this may be an example of the proposed method. Here, when the types of QCL RSs indicated in the TCI state #1 and the TCI state #3 are different from each other (for example, the type of one QCL RS is TypeA and the type of the other QCL RS is TypeC), it can be interpreted as SFN operation. On the other hand, when the type of QCL RS is the same (e.g., all QCL RS types are TypeA), it can be interpreted as a (Rel-16) multi-TRP transmission operation. Alternatively, the opposite is also possible.

In the above description, the different QCL types may refer to a case in which QCL types other than TypeD are different for QCL RSs included in different TCI states. This applies equally even if not separately described in the following description of the present disclosure.

Proposal a#1-2: the base station may configure whether to perform SFN operation on the terminal based on the L2 signaling. Here, in the case where i) SFN operation is configured and ii) terminals of different TCI states are indicated by specific code points of TCI fields in DCI, whether or not the SFN operation is actually performed may be determined based on the number of CDM groups including DMRS port(s) indicated by DCI and/or QCL types configured in the TCI states indicated by the specific code points. For example, when DMRS port(s) are included in a single CDM group, they may be defined to assume SFN operation. And/or, when QCL types configured in the TCI state indicated by the specific code point are different from each other (e.g., typeA for TCI state 1, typec for TCI state 2), it may be defined as assuming SFN operation.

In the method, after SFN operation is possible by configuring L2 signaling, if additional conditions are satisfied, actual SFN operation may be performed. Thus, when multiple TCI states are indicated, a particular method of multiple possible transmission methods may be dynamically indicated.

In the case of fig. 10 (a), it may be configured that SFN operation is possible through L2 signaling and (Rel-16) multi-TRP transmission method. After configuration, when DMRS port(s) indicated by DCI are included in different CDM groups, they may be interpreted as SFN operation. In this case, there may be a disadvantage in that it is impossible to dynamically select between NCJT and SFN.

In the case of fig. 10 (b), one of the SFN operation and URLLC operation may be configured through L2 signaling in addition to the (Rel-16) multi-TRP transmission method. After configuration, when DMRS port(s) indicated by DCI are included in the same CDM group, they may be interpreted as SFN operation. In this case, there may be a disadvantage in that it is impossible to dynamically select between URLLC transmission methods and SFNs.

In the case of fig. 10 (c), it may be configured that SFN operation is possible through L2 signaling and (Rel-16) multi-TRP transmission method. After configuration, when a plurality of TCI states are indicated through DCI and QCL types of different TCI states are different, it may be interpreted as SFN operation.

For example, whether to configure/operate the SFN in the proposal A#1-1-1/A#1-2 described above may be determined based on L2 signaling and a DCI field (e.g., a TCI field). Alternatively, DCI field (e.g., TCI field) based configuration with respect to whether to configure/operate the SFN may take precedence over L2 signaling based configuration.

It may be indicated to the terminal whether to configure/operate the SFN based on a specific RNTI value and the above proposal a#1/a#1-1/a#1-2. Alternatively, whether to configure/operate the SFN may be indicated to the terminal based on the specific RNTI value without applying the above proposal A#1/A#1-1-1/A#1-2. For example, an RNTI value within a particular range may be defined as an SFN-RNTI. And, when transmitting the PDCCH based on the SFN-RNTI configured to the terminal (i.e., when scrambling the CRC of the DCI transmitted through the PDCCH based on the SFN-RNTI), the terminal may assume that the PDSCH scheduled through the PDCCH is transmitted based on the SFN operation.

The above proposal a#1/a#1-1-1/a#1-2 proposes different QCL RS configuration methods for data (e.g., PDSCH) transmission. In addition, different QCL RS configuration methods for control data (e.g., PDCCH) transmission may be considered. This is because the PDCCH may also be SFN, and in the current standard, it is defined such that for QCL RS for PDSCH, QCL RS for PDCCH may be referred to. For example, when there is no TCI field in the DCI and the scheduling offset between the DCI and the PDSCH is greater than a threshold, it is defined to apply the TCI state of the PDCCH to the PDSCH.

The following proposals propose different QCL RS configuration methods for control data (e.g., PDCCH) transmission.

Proposal a#2: the base station may configure the terminal with different TCI states for the PDCCH DMRS port(s) based on L2 signaling. When different TCI states are configured, the terminal may assume that PDCCH DMRS port(s) are configured with SFN, and may perform channel estimation/compensation based on QCL RS corresponding to the different TCI states.

Table 9 illustrates higher layer parameters (i.e., CORESET Information Element (IE)) for CORESET (for monitoring PDCCH) to which a PDCCH is to be transmitted. That is, table 9 is an example of configuration information related to CORESET. The terminal may receive the PDCCH within the configured CORESET. In other words, table 9 below is an example of configuration information for CORESET used by a terminal to receive (or monitor) a PDCCH.

TABLE 9

Table 10 below is a table describing the fields in CORESET IE.

TABLE 10

/>

Fig. 11 illustrates a MAC Control Element (CE) for configuring a specific TCI state in CORESET in a wireless communication system to which the present disclosure may be applied. As shown in tables 9 and 10 above, the candidate TCI state for a particular CORESET may be configured by higher layer parameters (i.e., TCI-STATESPDCCH-ToAddList). That is, the configuration information associated with CORESET may include information regarding one or more TCI states. Also, as shown in fig. 11, a specific TCI state to be actually applied to the corresponding CORESET may be configured through a MAC CE operation.

According to existing standards, a TCI state may be configured in a particular CORESET through MAC CE operations.

Meanwhile, as in the above proposal a#1/a#1-1-1/a#1-2, performance for the HST-SFN can be improved by informing different QCL RSs for the same DMRS port(s). In addition, there may be an advantage in that RS overhead is reduced to reduce RSs configured with SFN. However, in order to reduce RSs configured with SFN, it is necessary to define a method in which the PDCCH can also refer to different QCL RSs in the same manner as the PDSCH. Otherwise, according to the above-described current standard scheme, since only one QCL RS can be referred to, there may be a problem in that an RS configured with an SFN needs to be additionally defined for PDCCH transmission.

To solve this problem, the proposal a#2 described above may be applied. That is, the base station may configure the terminal with different TCI states for the PDCCH DMRS port(s) based on L2 signaling. Also, when different TCI states are configured in the PDCCH DMRS port(s), the terminal may perform channel estimation/compensation based on QCL RSs corresponding to the different TCI states, assuming that the PDCCH DMRS port(s) are configured with SFNs (or whether SFN operations can be explicitly indicated/configured by the base station).

Hereinafter, a specific example for supporting proposal a#2 will be described.

Meanwhile, in order to transmit PDCCHs with higher reliability/robustness, a resource region for transmitting a plurality of PDCCHs corresponding to the same DCI may be defined. In particular, when multi-TRP transmission is assumed, a resource region for transmitting a PDCCH corresponding to each TRP may be defined. In addition, each TRP may transmit PDCCHs carrying the same DCI in a defined resource region.

In this disclosure, such resource regions are referred to as Monitoring Locations (ML). In the present disclosure, ML may be interpreted as a PDCCH transmission region in which the same DCI may be transmitted based on repetition/fraction (fraction). Here, ML may correspond to different QCL RS (s)/(TCI state (s)) respectively.

When a plurality of PDCCHs are transmitted through different MLs, a repeated transmission method in which each PDCCH corresponds to the same DCI may be applied, and/or a (partial) method in which each PDCCH is transmitted by dividing one DCI information may be applied. The repetition and partial methods described above are as follows.

-Repeating: for different ML (e.g., ML1/ML 2), each (or the same) coded bit may be transmitted in each ML after channel coding based on PDCCH transmission resources in each ML (which may be based on the same or different ML) and the same DCI.

For example, after generating coded bits based on PDCCH transmission resources in ML1 (e.g., PDCCH candidate #x in Aggregation Level (AL) # y) and DCI1, corresponding bits may be transmitted in PDCCH transmission resources in ML 1. After generating coded bits based on PDCCH transmission resources in ML2 (or may be based on PDCCH transmission resources in ML 1) and DCI1 (meaning the same DCI as described above), corresponding bits may be transmitted in PDCCH transmission resources in ML 2.

-Part (fraction): for different ML (e.g., ML1/ML 2), based on a single DCI and multiple PDCCH transmission resources in different ML, after channel coding, some coded bits may be transmitted through ML1 and the remainder may be transmitted through ML 2.

For example, PDCCH transmission resources in ML1 (e.g., PDCCH candidate #x in al#y) and PDCCH transmission resources in ML2 (e.g., PDCCH candidate #x 'in al#y') may be assumed to be the entire transmission resources. And, after generating coded bits based on the entire transmission resource and DCI1, some corresponding bits may be transmitted through ML1 and the remaining portion may be transmitted through ML 2.

As another example, after generating coded bits based on PDCCH transmission resources in a specific ML among a plurality of ML (e.g., PDCCH candidate #x in al#y in ML 1) and DCI1, some corresponding bits may be transmitted through ML1 and some remaining bits may be transmitted through ML 2. Here, for a single encoded bit, transmission for each ML may be performed through rate matching based on repeated transmission in a circular buffer.

As described above, when defining a plurality of MLs performing repetition/partial transmission, when considering multi-TRP transmission, different MLs may correspond to different TRPs, respectively. In this case, each ML may correspond to a different QCL RS (s)/(TCI state (s)). To this end, the method proposed in the present specification for configuring a plurality of QCL RSs (/ -TCI state (s)) to the same PDCCH DMRS port(s) (proposed a#2/proposed a#2-1-1/proposed a#2-1-2/proposed a#2-2-1/proposed a#2-3-1/proposed a#2-4-1/proposed a#2-4-2/proposed a#3/proposed a#4) may be applied. When applying the proposed method, the base station can inform the terminal for what purpose it will be by configuring/indicating whether to perform SFN operation and/or whether to define a plurality of ML together. That is, multiple QCL RSs (/' TCI state (s)) can be configured in the same manner, and by additionally configuring/indicating what purpose the terminal is to use, the terminal operates based on SFN or based on multiple ML. Alternatively, an independent configuration method may be defined according to each use.

In the present disclosure, for convenience of description, two ML (e.g., ML1/ML 2) are mainly described in examples of configuring/defining them, but the technical scope of the present disclosure is not limited, and it may be applied even when two or more ML are configured/defined.

Meanwhile, in the following proposal, for convenience of description, it is assumed that a plurality of MLs may be defined by a single search Space Set (SS) configuration and a single CORESET configuration, but the technical scope of the present disclosure is not limited thereto. The proposed method can be applied even when multiple ML are defined by single/multiple SS configuration and single/multiple CORESET configuration.

Fig. 12 illustrates a method defined in different ML according to an embodiment of the present disclosure.

Fig. 12 (a) illustrates defining different ML in the frequency domain (for the same monitoring occasion), and fig. 12 (b) illustrates defining different ML in the time domain (for the same monitoring occasion).

In fig. 12, for convenience of description, it is assumed that a plurality of ML configures the same Monitor Opportunity (MO), but the operation is not limited thereto. That is, the plurality of MLs may correspond to the plurality of MOs. In the example of fig. 12, the different ML may be a resource corresponding to a different CORESET configuration, and/or may be multiple ML defined by the same CORESET configuration.

Hereinafter, the present disclosure proposes a method of configuring/indicating different TCI states (/ QCL RS (s)) for a plurality of ML defined to perform repeated/partial transmission (for the same DCI).

Proposal a#2-1: a method of introducing new MAC CE operations to configure different QCL RSs configured with SFN operations for the same PDCCH DMRS port(s).

Proposal A#2-1-1: the base station may configure multiple TCI states in a particular CORESET through signaling operations of the MAC CE.

In fig. 13, the serving cell ID indicates an identifier of a serving cell to which the corresponding MAC CE is applied. CORESET ID indicates the set of control resources to which the TCI state is indicated. The TCI state ID indicates the TCI state that may be applied to the control resource set identified by the CORESET ID field. R may refer to a reserved bit.

Referring to fig. 13, a different QCL RS may be configured for one CORESET through TCI state ID fields (e.g., TCI state ID0, TCI state ID 1).

That is, according to the proposed method of the present disclosure, a plurality of TCI states may be configured for one CORESET through the MAC CE of fig. 13. Here, M (M is a natural number) TCI states indicated by the MAC CE may be determined among N (m+.n, N is a natural number) TCI states configured in CORESET related configuration information (for example, see tables 9 and 10).

Here, the MAC CE operation may be applied together with the existing Rel-15/16MAC CE operation. That is, in case that the terminal receives an existing MAC CE message including one TCI state ID, it may be assumed that one TCI state is configured in CORESET. In addition, as in the proposed method, in case that the terminal receives a MAC CE message including a plurality of TCI state IDs, it can be assumed that PDCCH DMRS transmitted in CORESET is transmitted through SFN.

The above proposal may be applied when PDCCH DMRS is transmitted over an SFN and/or when the same DCI is transmitted over multiple repetitions/portions of ML. When the above proposal is applied when the same DCI is transmitted through multiple MLs through repetition/portions, different QCL RS (s)/(TCI state (s)) may correspond to different MLs, respectively. For example, TCI state ID0 and TCI state ID1 may correspond sequentially to ML1/2, respectively.

Proposal A#2-1-2: the base station may perform activation/deactivation of the additional TCI state of a particular CORESET through a MAC CE operation.

Fig. 14 illustrates a MAC control element for indicating activation/deactivation for additional TCI states according to an embodiment of the present disclosure.

In fig. 14, the serving cell ID indicates an identifier of a serving cell to which the corresponding MAC CE is applied. CORESET ID indicates the set of control resources to which the TCI state is indicated. The TCI state ID indicates the TCI state that may be applied to the control resource set identified by the CORESET ID field.

In addition, as in the example of fig. 14, a field may be defined that can inform whether the MAC CE message is for activation or deactivation of the additional TCI state. For example, in fig. 14, a flag may be used to indicate whether the MAC CE message is for activation or deactivation.

The terminal may be configured with a TCI state for a particular CORESET through a Rel-15/16MAC CE message (e.g., the MAC CE of fig. 11) and may be configured with an additional TCI state through the MAC CE message of fig. 14. When the additional TCI state is configured according to the proposed method, the terminal can assume PDCCH DMRS transmitted in CORESET through SFN transmission. The base station may change the SFN operation to the non-SFN operation by disabling the TCI state via the MAC CE of fig. 14.

That is, according to the proposed method of the present disclosure, a plurality of TCI states may be configured for one CORESET through the MAC CE of fig. 14. The TCI state for a particular CORESET is configured by Rel-15/16MAC CE message (e.g., the MAC CE of fig. 11), and may be additionally configured by the MAC CE of fig. 14 for one or more TCI states of the corresponding CORESET. Here, M (M is a natural number) TCI states indicated by the MAC CE of fig. 14 may be determined among N (m+.n, N is a natural number) TCI states configured in CORESET related configuration information (for example, see tables 9 and 10).

The above proposal may be applied when PDCCH DMRS is transmitted over an SFN and/or when the same DCI is transmitted over repetition/parts via multiple ML. When the above proposal is applied when the same DCI repetition/portion is transmitted through multiple MLs, different QCL RS (s)/(TCI state (s)) may correspond to different MLs. For example, the CORESET configured TCI state (e.g., TCI state 0) defined based on the Rel-15 operation and the (additional) TCI state (e.g., TCI state 1) defined based on the proposed method may correspond sequentially to ML1/2, respectively.

Proposal a#2-2: to configure different QCL RSs SFN for the same PDCCH DMRS port(s), a new interpretation method for existing MAC CE operations

Proposal a#2-2-1: the base station may configure information about candidates for TCI state combinations that may consist of multiple TCI states in CORESET configurations (e.g., through higher layer signaling), and may configure specific combinations between the candidates for TCI state combinations in CORESET. In this case, the TCI state ID defined in the MAC CE may represent/indicate an index (or may be interpreted as an index) for a combination of candidate TCI states.

TABLE 11

TCI state combination ID (or index)	TCI State ID ₀	TCI State ID ₁
			#1	#1
#2	#2
			#3	#3
#4	#1	#2
			#5	#2	#3
#6	#4
			#7	#5
#8	#4	#5

As in the example of table 11, each TCI state combination may include one or more TCI states. When the information on the TCI state combination as described above is a configuration in CORESET configurations (see, e.g., tables 9 and 10 above), a field indicating the TCI state ID in the MAC CE message (see, e.g., fig. 11 above) may be interpreted for the purpose of indicating the TCI state combination ID (or index). For example, when a TCI state combination ID composed of a plurality of TCI states is configured as shown in #4/#5/#8 of table 11, the terminal can assume PDCCH DMRS transmitted from CORESET through SFN transmission.

That is, according to the proposed method of the present disclosure, a plurality of TCI states may be configured for one CORESET through the MAC CE. The plurality of TCI states for CORESET may be configured by indicating a TCI state combination identifier for a particular CORESET via a particular MAC CE message. Here, the TCI state combination identifier indicated by a specific MAC CE may be determined among the TCI state combination candidates configured in CORESET-related configuration information (for example, see tables 9 and 10).

The above proposal may be applied when PDCCH DMRS is transmitted over an SFN and/or when the same DCI is transmitted over repetition/parts via multiple ML. When the above proposal is applied when the same DCI repetition/portion is transmitted through multiple MLs, different QCL RS (s)/(TCI state (s)) may correspond to different MLs. For example, when a TCI state combination ID (such as #4/#5/# 8) composed of a plurality of TCI states is configured, the first/second TCI states may sequentially correspond to ML1/2, respectively. In other words, in table 11, the TCI state ID0 may correspond to ML1 and the TCI state ID1 may correspond to ML2, respectively.

Proposal a#2-3: method of using higher layer signaling (e.g., RRC signaling) to configure different QCL RSs for the same PDCCH DMRS port(s) being SFN

Proposal A#2-3-1: the base station may configure a TCI state combination, which may be configured with multiple TCI states in CORESET configurations.

That is, according to the proposed method of the present disclosure, a plurality of TCI states may be configured for one CORESET through CORESET configuration information (see, for example, tables 9 and 10).

According to the current standard, RRC signaling and MAC CE operations should operate together to configure CORESET TCI states. In this proposal, multiple TCI states may be configured for respective CORESET based on RRC signaling. When the above method is applied, a new MAC CE message/operation is not required, and thus there may be an advantage in that the influence of the existing operation according to the standard may be reduced. The above proposal may be applied when PDCCH DMRS is transmitted over an SFN and/or when the same DCI is transmitted over repetition/parts via multiple ML. When the above proposal is applied when the same DCI repetition/portion is transmitted through multiple MLs, different QCL RS (s)/(TCI state (s)) may correspond to different MLs. For example, the first/second TCI states may correspond sequentially to ML1/2, respectively.

Proposal a#2-4: method for configuring different QCL RSs for the same PDCCH DMRS port(s) being SFN using search Space Set (SS) configuration

Proposal a#2-4-1: the base station may configure one QCL RS (/ TCI state) through CORESET configurations, and may additionally configure QCL RS (/ TCI state (s)) through a search Space Set (SS) configuration including CORESET configurations.

In a search Space Set (SS) configuration, the associated CORESET ID may be included, and the configuration of CORESET identified by the corresponding CORESET ID may be included in the corresponding search Space Set (SS) configuration. That is, the TCI state in CORESET configurations associated with the SS configuration is configured, and the TCI states included in the corresponding SS configuration may also be configured together.

The above proposal may be applied when PDCCH DMRS is transmitted over an SFN and/or when the same DCI is transmitted over repetition/parts via multiple ML. When the above proposal is applied when transmitting PDCCH DMRS over SFN, PDCCH DMRS transmitted in CORESET over SFN transmission can be assumed. On the other hand, when the above proposal is applied when the same DCI is repeatedly/partially transmitted through a plurality of MLs, different QCL RS (s)/(TCI state (s)) may correspond to different MLs. For example, a TCI state configured by CORESET configurations (e.g., TCI state 1) and an additional TCI state configured by SS configurations may sequentially correspond to ML1/2, respectively.

Meanwhile, when additional TCI state(s) (/' QCL RS) are configured/indicated/defined by separate routes in addition to the TCI state configured in CORESET in the above method, each TCI state should be changed in an independent manner when attempting to change. Thus, it may have the following drawbacks: the delay/signaling overhead for changing the TCI state(s) increases.

Proposal a#2-4-2: the base station may configure the plurality of QCL RSs (/' TCI state (s)) by SS configuration, where the TCI state of CORESET configurations associated with the SS configuration (i.e., CORESET configuration identified by CORESET ID in the SS configuration) may be ignored. In other words, QCL RS (s)/(TCI state (s)) based on SS configuration may take precedence over TCI state(s) of CORESET configuration(s) associated with SS configuration.

The above proposal may be applied when PDCCH DMRS is transmitted over an SFN and/or when the same DCI is transmitted over repetition/parts via multiple ML. When the above proposal is applied when transmitting PDCCH DMRS over an SFN, it can be assumed that PDCCH DMRS transmitted in CORESET associated with the SS configuration is transmitted over the SFN. In this case, reference is made to a plurality of QCL RS (/ TCI states) configured by SS configuration, and the CORESET configured TCI state configuration associated with SS configuration can be ignored. On the other hand, when the above proposal is applied when the same DCI is repeatedly/partially transmitted through a plurality of MLs, different QCL RS (s)/(TCI state (s)) may correspond to different MLs. For example, a plurality of TCI states (e.g., TCI state 1/2) configured by SS configuration may sequentially correspond to ML1/2, respectively, and TCI states (e.g., TCI state 1) configured by CORESET configuration may be omitted.

As described above, when a plurality of TCI states (/ QCL RS) can be configured/indicated in an SS configuration, there are the following advantages: when changing the TCI state(s), the TCI state combination may be changed based on a single signaling. For example, when TCI state combinations of { a, B } are configured, the TCI state combinations may be changed to { C, D } or the like based on a single MAC CE message. In this case, it is advantageous in that delay/signaling overhead for changing the TCI state(s) can be reduced compared to the proposed a#2-4-1 scheme.

Proposal a#3: three or more QCL RSs may be configured in a TCI-State, which is a parameter for QCL RS configuration of PDSCH/PDCCH (DMRS). When the TCI-State configured with three or more QCL RSs is configured for PDSCH/PDCCH (DMRS) transmission, the terminal may assume that the indicated DMRS port(s) is configured with SFN (or may explicitly configure/indicate whether to perform SFN operation) based on the QCL RSs. In addition, the terminal may perform channel estimation/compensation based on the QCL RS.

The QCL RS configuration of the current standard PDSCH/PDCCH defines higher layer parameters called "TCI State (TCI-State)", and the definition of TCI-State is shown in table 7 above.

As can be seen from Table 7, one TCI-State can have a total of two QCL RSs, such as QCL-Type1/QCL-Type2. In the case of qcl-Type1, one of Type a/Type b/Type c may be configured, and in qcl-Type2, typeD may be configured. Since TypeD refers to an RS for a reception beam (i.e., spatial reception parameter) of a terminal, one RS capable of acquiring channel information such as doppler shift/doppler spread/average delay/delay spread can be configured for each TCI-State.

It may be defined such that QCL RS may be additionally configured to the TCI-State parameter. Thus, when PDSCH/PDCCH DMRS port(s) are transmitted through the SFN, the reception performance of the terminal can be improved by configuring/indicating QCL RS for each channel before combining.

For example, qcl-Type1 and qcl-Type3 may be configured in a particular TCI-State and may each correspond to a different RS having one Type of TypeA/TypeB/TypeC. When the TCI-State is configured/indicated as a QCL RS for PDSCH/PDCCH DMRS port(s), the terminal may receive PDSCH/PDCCH assuming that DMRS port(s) are configured with SFN.

As another example, qcl-Type1, qcl-Type2, qcl-Type3 may be configured in a particular TCI state, and each of qcl-Type1 and qcl-Type3 may correspond to a different RS having one Type of TypeA/TypeB/TypeC, and an RS having TypeD is configured for qcl-Type 2. Here, since one RS having TypeD is configured, it can be assumed that the same TypeD is applied to qcl-Type1 and qcl-Type3.

Meanwhile, qcl-Type1, qcl-Type2, qcl-Type3, qcl-Type4 may be configured in a specific TCI state, and each of qcl-Type1 and qcl-Type3 may correspond to a different RS having one of Type a/Type b/Type c, and qcl-Type2 and qcl-Type4 have TypeD, and may configure different RSs for qcl-Type2 and qcl-Type4, respectively. Here, a correspondence between qcl-Type1 and qcl-Type2 may be provided, and a correspondence between qcl-Type3 and qcl-Type4 may be provided. Based on the correspondence, when the terminal receives the RS for qcl-Type1, the terminal may apply a reception beam (e.g., apply the same spatial reception parameters) for the RS of qcl-Type 2. In addition, when the terminal receives the RS for qcl-Type2, the terminal may apply a reception beam for the RS for qcl-Type4 (e.g., apply the same spatial reception parameters).

The above proposal may be applied when PDCCH DMRS is transmitted over an SFN and/or when the same DCI is transmitted over repetition/parts via multiple ML. When the above proposal is applied when the same DCI repetition/portion is transmitted through multiple MLs, different QCL RS (s)/(TCI state (s)) may correspond to different MLs. For example, qcl-Type1 and qcl-Type3 may be configured in a particular TCI state, and each may correspond to a different RS having one Type of TypeA/TypeB/TypeC. When the TCI-State is configured/indicated as QCL RS for multiple MLs, QCL-Type1/3 may correspond sequentially to ML1/2, respectively. As another example, qcl-Type1, qcl-Type2, and qcl-Type3 may be configured in a particular TCI-State, and each of qcl-Type1 and qcl-Type3 may correspond to a different RS having one Type of TypeA/TypeB/TypeC, and an RS having TypeD may be configured for qcl-Type 2. In this case, since one RS having TypeD is configured, the terminal can assume that the same TypeD is applied to qcl-Type1 and qcl-Type3.qcl-Type1/3 may correspond sequentially to ML1/2, respectively. Meanwhile, qcl-Type1, qcl-Type2, qcl-Type3, and qcl-Type4 may be configured in a specific TCI-State, and each of qcl-Type1 and qcl-Type3 may correspond to a different RS having one Type of Type a/Type b/Type c, and qcl-Type2 and qcl-Type4 have TypeD, and may configure different RSs for qcl-Type2 and qcl-Type4, respectively. In this case, qcl-Type1 and qcl-Type2, and qcl-Type3 and qcl-Type4 may have correspondence, respectively. The correspondence may refer to that when receiving RSs for qcl-Type1 and qcl-Type3, the terminal applies a reception beam (e.g., the same spatial Rx parameter) for RSs of qcl-Type2 and qcl-Type4, respectively. Further, qcl-Type1/2 may correspond to ML1, and qcl-Type3/4 may correspond to ML2.

Proposal a#4: for QCL RS configuration of PDSCH (DMRS)/PDCCH (DMRS)/DL RS (CSI-RS, etc.), information about TCI state combinations, which may be configured with one or more TCI states, may be configured for a terminal based on higher layer signaling (i.e., L2 signaling).

Table 12 shows an example of applying the proposed method.

TABLE 12

As shown in table 12, new higher layer parameters (e.g., RRC parameters) that may be composed of multiple TCI states may be defined. As described above, when defining a new higher layer parameter composed of a plurality of TCI states, this may have an advantage of applying a plurality of RSs as QCL RSs of PDSCH (DMRS)/PDCCH (DMRS)/DL RSs (CSI-RS, etc.). The above proposal is applicable even when the same DCI is transmitted PDCCH DMRS through SFN and/or repeated/partial transmitted through multiple ML. When the above proposal is applied when the same DCI is repeatedly/partially transmitted through a plurality of MLs, different QCL RS (s)/(TCI state (s)) may correspond to different MLs. For example, each first/second TCI state may correspond sequentially to ML1/2.

Meanwhile, the above-proposed method for configuring a plurality of QCL RSs (/ TCI states) in the same PDCCH DMRS port(s) (propose A#2/propose A#2-1-1/propose A#2-1-2/propose A#2-2-1/propose A#2-3-1/propose A#2-4-1/propose A#2-4-2/propose A#3/propose A#4) is described based on 2 different TRPs, but the method proposed above is not limited to 2 TRP. Thus, the proposed method can be extended and applied to 2 or more TRPs different from each other. In addition, each of the proposed methods has been described under the assumption that it can be applied to the case of performing SFN transmission or repeated/partial transmission through a plurality of MLs, but an environment to which the proposed method is applicable is not limited thereto. For example, SFN transmission and repetition/partial transmission through a plurality of ML may be performed simultaneously. In this case, the transmission may be performed based on the SFN transmission in each ML. For example, SFN transmission of TRP1/2 in ML1 and SFN transmission of TRP1/2 in ML2 may be performed. And/or SFN transmission of TRP1/2 in ML1 and SFN transmission of TRP3/4 in ML2 may be performed. And/or SFN transmission of TRP1/2 in ML1 and SFN transmission of TRP2/3 in ML2 may be performed. And/or SFN transmission of TRP1/2 in ML1 and single TRP transmission of TRP3 in ML2 may be performed. As described above, the total number of TCI state(s) (/ [ QCL RS(s) ] may be determined depending on what type of SFN transmission is configured/indicated (according to the transmission method) and/or repeated/partial transmission through multiple ML. And/or, what form (transmission method) the SFN transmission and/or the repeated/partial transmission through the plurality of ML may be determined depending on the total number of TCI state (s)/(QCL RS) configured/indicated to the terminal according to the proposed method.

Meanwhile, when based on the above proposed method (proposed A#2/proposed A#2-1-1/proposed A#2-1-2/proposed A#2-2-1/proposed A#2-3-1/proposed A#2-4-1/proposed A#2-4-2/proposed A#3/proposed A#4) for configuring a plurality of QCL RSs (/ TCI states) in the same PDCCH DMRS port(s), when performing SFN transmission and/or repeated/partial transmission over multiple ML, default beams for PDSCH reception and/or default TCI state(s) (/ [ QCL RS ]) according to the proposed method should be defined.

Proposal a#5: when the offset value between the DCI and the PDSCH scheduled by the DCI is greater than or equal to a specific threshold (e.g., higher layer parameters timeDurationForQCL) and there is no TCI field within the DCI, the following method may be applied.

Proposal a#5-1: when configured/indicated to perform repeated/partial transmission through a plurality of MLs, a plurality of QCL RSs (corresponding to different TRPs) configured/indicated/defined in a plurality of MLs (/ TCI states) may be equally applied to PDSCH reception. In this case, the terminal may assume multi-TRP transmission when receiving PDSCH. multi-TRP transmission may refer to transmission in which different TRPs correspond to different groups of transmission layers (/ DMRS port group/(DMRS CDM group). And/or may refer to transmission of different TRPs corresponding to different resources in the frequency/time domain (in the form of repetition of the same data in different TRPs). For multi-TRP transmission, a specific scheme may be configured/indicated/defined for a terminal based on fixed rules and/or L1/L2 signaling. And/or;

Proposal a#5-2: when configured/indicated to perform SFN transmission, multiple QCL RSs (/ TCI states) corresponding to different TRPs may be equally applied to PDSCH reception. In this case, the terminal may assume SFN transmission when receiving PDSCH.

Proposal a#5-3: when configured/indicated to perform repeated/partial transmission through a plurality of MLs, and/or when configured/indicated to perform SFN transmission, a specific QCL RS (/ TCI state) of a plurality of QCL RS (/ TCI state) configured/indicated/defined for SFN transmission of a plurality of MLs and/or (corresponding to different TRPs) may be applied at the time of receiving PDSCH. In this case, the terminal may assume a single TRP transmission when receiving the PDSCH.

Proposal A#5-3-1: the particular QCL RS (/ TCI state) or states may be determined based on the location/index of the resources for the plurality of MLs. For example, the determination may be based on time resources (e.g., transmitted on earlier (later) symbols in the time domain) and/or frequency resources (e.g., transmitted on lower (higher) subcarriers) for the plurality of ML. And/or;

Proposal A#5-3-2: for a particular QCL RS(s) (/ TCI state), the TCI state configured in CORESET associated with the search Space Set (SS) configuration may be applied. And/or the number of the groups of groups,

Proposal A#5-3-3: a specific TCI state (e.g., first/second/last/lowest/highest TCI state) of a plurality of QCL RSs (/ (one or more) TCI states) included in a search Space Set (SS) configuration (corresponding to different TRPs) may be applied.

Meanwhile, in the proposal a#5-1/5-2, conditions for applying each proposal are separately described for convenience of explanation, which does not limit an environment in which the proposed method can be applied. In other words, the proposed method is described such that the method of receiving PDSCH (i.e., assumed SFN transmission, multi-TRP transmission) can be determined according to the method of receiving PDCCH (i.e., assumed SFN transmission, assumed repetition/partial transmission by a plurality of MLs), but can be determined irrespective of the method of receiving PDCCH. For example, regarding proposal a#5-1, the proposed method can be applied even when configured/instructed to perform SFN transmission, not when configured/instructed to perform repetition/partial transmission through a plurality of MLs. An example of a method of determining a method for receiving PDSCH regardless of a method for receiving PDCCH is shown below (the opposite case is also possible).

When the offset value between the DCI and the PDSCH scheduled by the DCI is greater than or equal to a certain threshold (e.g., higher layer parameters timeDurationForQCL) and there is no TCI field in the DCI,

Example-1) when receiving PDSCH, a terminal may assume multi-TRP transmission. The multi-TRP transmission may have the same meaning as proposed a#5-1 (which means PDSCH receiving operation in proposed a#5-1. TCI state(s) (/ [ QCL RS(s) ] could equally be applied)

Example-2) the terminal may assume SFN transmission when receiving PDSCH (this means proposing PDSCH receiving operation in a#5-2. TCI state(s) (/' QCL RS) may be equally applied. )

Example-3) the terminal may assume a single TRP transmission when receiving PDSCH (this means proposing PDSCH receiving operation in a#5-3. TCI state(s) (/' QCL RS) may be equally applied. )

It is defined as a fixed rule to apply a specific method, and/or the base station may configure the specific method for the terminal through separate L1/L2 signaling among PDSCH reception methods (regardless/independent of the method of receiving the PDCCH). For example, even when configured/indicated to perform repetition/partial transmission through a plurality of MLs for PDCCH transmission, PDSCH transmission may be configured/indicated as SFN-based transmission according to separate L1/L2 signaling. In the case of the above-described method, the following advantages may be provided: the transmission method of the PDSCH (i.e., multi-TRP, SFN, single TRP, etc.) may be configured regardless of the transmission method of the PDCCH (i.e., repetition, partial or SFN, etc.). The specific PDSCH reception method can be configured/indicated/defined in CORESET units and/or BWP units and/or serving cell units. For example, when configured/indicated/defined in CORESET units, PDSCH may be received according to a method configured in CORESET where DCI (/ (PDCCH (s)) for scheduling PDSCH is detected. In this case, the reception method of PDSCH scheduled by DCI detected through different CORESET may be different. When configured/indicated/defined in BWP units, it may be assumed that the same PDSCH reception method is applied within the same BWP, and when BWP is different, different PDSCH reception methods may be applied.

When the offset value between DCI and PDSCH scheduled by DCI is less than a particular threshold (e.g., higher layer parameter timeDurationForQCL) and even though CORESET defining the lowest index in the most recent slot of the monitoring occasion is CORESET according to the proposed method (propose a#2/propose a#2-1-1/propose a#2-1-2/propose a#2-2-1/propose a#2-3-1/propose a#2-4-2/propose a#3/propose a#4) configured with a plurality of QCL RSs (/ (one or more) TCI states) and/or CORESET associated with SS configuration, the proposed method (propose a#5/propose a#5-1/propose a#5-2/propose a#5-3/a#5-3-1/propose a#5-3-1/a#5-3-2/3#3-3).

Specific ones of the proposed methods (proposed a#5/proposed a#5-1/proposed a#5-2/proposed a#5-3-1/proposed a#5-3-2/proposed a#5-3-3) are fixedly applied (e.g., predefined or determined by predefined rules), or may be configured/indicated as being applied based on L1/L2 signaling.

Proposal #2: method for configuring different DMRS ports in the same transport layer(s)

Proposal b#1: n-layer transmission method using 2N (N is a natural number) DMRS ports

Proposal b#1-1: transmission method using antenna port to layer mapping

Based on predetermined signaling (e.g., through RNTI/DCI format/L2 signaling (e.g., RRC/MAC CE)/L1 signaling (e.g., DCI)), the base station may configure/instruct the terminal to perform HST-SFN operation. A terminal receiving the configuration/indication may apply certain rules for antenna port-to-layer mapping. Examples of the specific rules described above are as follows.

A1: the number of transmission layers may be determined based on the number of DMRS ports (or half of the total number of DMRS ports indicated) included in a specific CDM group (e.g., lowest CDM group/highest CDM group/CDM group #0/#1/# 2/CDM group including more (or less) (one or more) DMRS ports, etc.) of DMRS ports (one-half of the total number of DMRS ports indicated) indicated through the antenna port field(s) in the DCI. Here, the transmission symbols of each layer may be sequentially (e.g., ascending/descending/(the order indicated in the antenna port field (s)), etc.) and/or repeatedly mapped to DMRS port(s) in each CDM group.

In fig. 15, y ^(p) (i) is the i-th transmission symbol of the antenna port p, and x ^(v) (i) is the i-th transmission symbol of the v-th layer.

In the case of fig. 15 (a), which illustrates the case where two DMRS ports 1000 and 1002 are indicated by the antenna port field(s). Here, the number of actually transmitted transmission layers may be defined as 1, corresponding to half of the indicated number of DMRS port(s). The transmission symbols of the transmission layer may be repeatedly mapped to the antenna ports 1000 and 1002 and simultaneously transmitted.

In the case of fig. 15 (b), examples of cases of 1000, 1001, 1002, 1003 antenna ports are indicated by the antenna port field(s). Here, the number of actually transmitted transmission layers may be defined as 2, corresponding to half of the indicated number of DMRS port(s). The transmission symbols of the first transmission layer are repeatedly mapped to the antenna ports 1000 and 1002, and the transmission symbols of the second transmission layer are repeatedly mapped to the antenna ports 1001 and 1003, and may be simultaneously transmitted.

It is assumed that according to proposal A1, the number of transmission layers is determined based on the number of DMRS ports (or half of the total number of DMRS ports indicated) included in a specific CDM group (e.g., lowest/highest/CDM group #0/#1/# 2/including more (or less) DMRS ports (or the like)) among DMRS ports(s) indicated through an antenna port field(s) in DCI. In this case, when calculating a Transport Block Size (TBS) of a PDSCH scheduled by DCI, the TBS may be calculated based on a newly defined number of proposed-based transport layers. For example, in the following step (step 2) of the steps described above for TBS determination, v may be replaced by the number of transmission layers calculated based on the A1 proposal.

In the proposal of A1, it is assumed that the antenna port field(s) is defined based on the DMRS table defined in Rel-15/16. To this end, a new DMRS table may be introduced and/or a new DCI field may be defined. In this case, the actual number of transport layers and/or whether to perform SFN operations (i.e., antenna port-to-layer mapping information) and/or antenna port index(s) may be explicitly indicated by the antenna port field(s) and/or the new DCI field.

Meanwhile, when the number of DMRS ports(s) included in different CDM groups in proposal A1 of proposal b#1-1 is different, only a portion of the entire transmission layer may be transmitted or the same transmission layer may be repeatedly transmitted among antenna port(s) included in a specific CDM group.

In the case of fig. 16 (a), an example of determining the actual number of transmission layers based on CDM groups including fewer DMRS port(s) is shown. Here, it can be seen that the same transport layer is repeatedly transmitted for CDM groups including more DMRS port(s).

Meanwhile, in the case of fig. 16 (b), an example of determining the actual number of transmission layers based on a CDM group including more DMRS ports(s) is shown. Here, it can be seen that for CDM groups including fewer DMRS port(s), only a portion of the entire transmission layer is transmitted.

As in the example of fig. 16, even when the number of DMRS ports(s) included in different CDM groups is different (e.g., when only a part of the entire transmission layer is transmitted among antenna port(s) included in a specific CDM group, or the same transmission layer is repeatedly transmitted), the TBS may be calculated based on the newly defined number of transmission layers. When the actual number of transmission layers is determined based on a CDM group including a smaller number of DMRS ports(s), as in the example of fig. 16 (a), the TBS may be calculated based on the number of transmission layers corresponding to the smaller number of DMRS port(s). Alternatively, when the actual number of transmission layers is determined based on a CDM group including a larger number of DMRS ports(s) as in the example of fig. 16 (b), the TBS may be calculated based on the number of transmission layers corresponding to the larger number of DMRS port(s). For example, in the following second of the steps described above for TBS determination, v may be replaced by the number of transport layers calculated based on the A1 proposal.

When multiple TCI states and/or QCL RSs corresponding to TypeA/TypeB/TypeC are configured/indicated for a terminal in addition to the proposed method, different TCI states and/or QCL RSs may correspond to DMRS port(s) of different CDM groups, respectively.

Proposal b#1-2: transmission method using relation between PDSCH antenna port and DMRS antenna port

In the existing standard, it is assumed that PDSCH antenna port(s) and DMRS antenna port(s) (DMRS port(s) indicated by antenna port field(s) in DCI) are identical to each other (defined by the same 1000 series number). However, this assumption may not be true when the SFN method is to be applied. Thus, a new definition may be required for the relationship between PDSCH antenna port(s) and DMRS antenna port(s). In the following proposal, a method of configuring/indicating antenna port(s) to which DMRS is to be transmitted and antenna port(s) (PDSCH) to which a transmission layer is to be mapped through antenna port field(s) in DCI is presented in the following proposal.

A1: based on predetermined signaling (e.g., through RNTI/DCI format/L2 signaling (e.g., RRC/MAC CE)/L1 signaling (e.g., DCI)), the base station may configure/instruct the terminal to perform HST-SFN operation. Terminals receiving the configuration/indication may apply specific rules for channel estimation and antenna port-to-layer mapping with reference to a specific DMRS table (e.g., rel-17 DMRS table for HST-SFN) and/or for the referenced DMRS table. To this end, PDSCH antenna port (s)/DMRS antenna port(s) may be configured/indicated to the terminal. In addition, PDSCH antenna port(s) may be redefined from DMRS antenna port(s). And/or DMRS antenna port(s) may be divided into different groups. To this end, the base station may explicitly/implicitly perform necessary signaling. The PDSCH antenna port(s) may be redefined (examples of explicit/implicit signaling will be described later) and/or based on a sum of DMRS antenna port(s) corresponding to different groups.

Table 14 below shows an example of the proposed method.

Table 13 illustrates the DMRS table of Rel-15.

TABLE 13

Table 14 illustrates a DMRS table according to an embodiment of the present disclosure.

TABLE 14

/>

In table 14, the DMRS port(s) indicated by the DMRS port column(s) may refer to the antenna port(s) corresponding to the PDSCH antenna port(s) (i.e., the antenna port(s) to which the transport layer(s) is mapped), as previously described. In table 14, temporary DMRS port group(s) (TDG) 0/1 may refer to antenna port(s) through which DMRS corresponding to PDSCH is transmitted. In table 14, symbols transmitted from PDSCH antenna port(s) and symbols transmitted from DMRS antenna port(s) corresponding to different TDGs may have a relationship as shown in equation 3 below.

[ Equation 3]

Wherein/>

DMRS antenna port/>, and (k, l), μ and TDG 0Corresponding transmission symbol

And (k, l), μ and DMRS antenna port/>, of TDG 1Corresponding transmission symbol

In equation 3, (k, l) may represent the kth subcarrier and the ith OFDM symbol, and μmay represent a parameter set indicator. And, N is the total number of antenna port(s) corresponding to PDSCH, M ₁ is the total number of DMRS antenna port(s) corresponding to TDG (temporary DMRS port group) 0, and M ₂ is the total number of DMRS antenna port(s) corresponding to TDG 1. I _M denotes an identity matrix, the size of which corresponds to M.

Beta represents a scaling factor.

In equation 3, a transmission symbol is described as an example, but an example for describing the relationship may not be limited to a transmission symbol, and it may be expressed as a transmission signal/reception symbol/resource element, etc., and this may be used to define to explain the relationship between PDSCH antenna port(s) and DMRS antenna port(s). In the case of applying the method proposed above, an example of the value 13 of table 14 is shown in the following equation 4.

[ Equation 4]

In order to apply the proposed method, the following method may be considered in order to configure/indicate PDSCH antenna port(s) and DMRS antenna port(s) for the terminal.

Examples of explicit methods:

m1: information about antenna port(s) corresponding to PDSCH antenna port(s) in the DMRS table, DMRS antenna port(s) of different TDGs, and TDGs corresponding to each DMRS antenna port may be indicated. An example of this is shown in table 15 below.

Examples of implicit methods:

M2-1: antenna port(s) corresponding to PDSCH antenna port(s) in the DMRS table, as well as DMRS antenna port(s) of different TDGs may be indicated. Here, the TDG and PDSCH antenna port(s) corresponding to each DMRS antenna port may be defined by a predetermined rule between the base station and the terminal. An example of this is shown in table 16 below.

M2-2: antenna port(s) corresponding to PDSCH antenna port(s) in the DMRS table, and DMRS antenna port(s) of a particular TDG may be indicated. Here, the DMRS antenna port(s) included in another TDG other than the TDG including the indicated DMRS antenna port(s) may be defined by a predetermined rule between the base station and the terminal. An example of this is shown in table 17 below.

TABLE 15

TABLE 16

TABLE 17

In tables 15 to 17, the portion corresponding to the value 12/13 is a newly added portion, compared with the Rel-15 DMRS table.

In the case of table 15, in the case of (a), the antenna port(s) corresponding to the PDSCH antenna port(s) may be indicated by the DMRS port column(s). Antenna ports of DMRS(s) corresponding to PDSCH may be indicated by temporary DMRS port group(s) 0/1, respectively.

In the case of table 16, PDSCH antenna port(s) may be part of the antenna port(s) indicated by the DMRS port(s) and may be determined based on the CDM group to which the DMRS port(s) belongs. For example, DMRS port(s) belonging to a particular CDM group (e.g., #0 or #1 or #2 or lowest or highest) may be defined to correspond to PDSCH antenna port(s). The TDG corresponding to each DMRS antenna port may also be defined based on CDM groups. For example, DMRS port(s) included in the lowest CDM group or CDM group 0 may be included in TDG 0, and DMRS port(s) included in the remaining CDM group or CDM group 1 may be included in TDG 1.

In the case of table 17, antenna port(s) corresponding to PDSCH antenna port(s) may be indicated through DMRS port column(s) and included in a particular TDG. The DMRS antenna port(s) to be included in another TDG may be configured to include all or part of DMRS port(s) different from the indicated DMRS port(s) in the CDM group, and may be configured with the same number of ports as the indicated DMRS port(s).

In the above example, it is assumed that a new row is added compared to the Rel-15 DMRS table, but the proposed method is applied based on the existing DMRS table, so a different interpreted method may also be applied.

In addition to the proposed method, the actual rank value and/or the number of DMRS ports and/or port-to-layer mapping information may be indicated by separate fields in the DCI. And/or whether to apply SFN operation and port-to-layer mapping information may be configured based on L2 signaling.

Regarding the method proposed below the proposal #1 (i.e., the method of configuring different QCL reference signals in the same DMRS port (s)) and the method proposed below the proposal #2 (i.e., the method of configuring different DMRS ports in the same transmission layer (s)), there may be a difference between a method for implementing a receiving end of a terminal to support the method proposed below the proposal #1 and a method for implementing a receiving end of a terminal to support the method proposed below the proposal # 2. Furthermore, this may lead to differences in implementation complexity. In view of the above implementation complexity, a different method may be implemented for each terminal. In order for the base station and the terminal to perform appropriate operations according to the proposed method implemented in the terminal, the terminal may report the proposed method as operable to the base station (e.g., through UE capability signaling). The base station may support a method suitable for the corresponding terminal according to the content reported from the terminal (e.g., through L1/L2 signaling).

Proposal #3: method for configuring/indicating SFN operation for multiple TO (transmission opportunity)/ML (monitoring location)

In Rel-16, a new operation for repeating PDSCH transmission is introduced based on a multi-TRP transmission operation. In Rel-17, a PDCCH repetition transmission scheme based on a multi-TRP transmission operation will be discussed. Four operations were introduced as a PDSCH retransmission scheme for Rel-16, which corresponds to FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA and slot level retransmission.

Hereinafter, a description of a repeated transmission scheme described in the current TS 38.214 standard is shown.

When the UE is configured by the higher layer parameter repetitionScheme set to one of "FDMSCHEMEA", "fdmSchemeB", "TDMSCHEMEA", if the UE is indicated two TCI states in the code point of the DCI field "transmission configuration indication" and is indicated DM-RS port(s) within one CDM group in the DCI field "(antenna port(s)",

-When two TCI states are indicated in the DCI and the UE is set to "FDMSCHEMEA", the UE shall receive a single PDSCH transmission occasion of a TB, wherein each TCI state is associated with a non-overlapping frequency domain resource allocation.

-When two TCI states are indicated in the DCI and the UE is set to "fdmSchemeB", the UE shall receive two PDSCH transmission occasions of the same TB, wherein each TCI state is associated with a PDSCH transmission occasion with non-overlapping frequency domain resource allocation relative to the other PDSCH transmission occasion.

When two TCI states are indicated in the DCI and the UE is set to "TDMSCHEMEA", the UE shall receive two PDSCH transmission occasions of the same TB, wherein each TCI state is associated with a PDSCH transmission occasion with non-overlapping time domain resource allocation relative to the other PDSCH transmission occasion and both PDSCH transmission occasions shall be received within a given time slot.

When the UE is configured by a higher layer parameter PDSCH-config indicating at least one entry in PDSCH-TimeDomainAllocationList containing RepNumR in PDSCH-TimeDomainResourceAllocation, the UE may expect to be indicated one or two TCI states in the code point of the DCI field "transmission configuration indication" and the DCI field "time domain resource assignment" indicating the entry containing RepNum16 in PDSCH-TimeDomainResourceAllocation in PDSCH-TimeDomainAllocationList and DM-RS port(s) within one CDM group of DCI field(s) antenna port(s) ".

When two TCI states are indicated in the DCI with the "transmission configuration indication" field, the UE may expect to receive multiple slot level PDSCH transmission occasions of the same TB with the two TCI states used across multiple PDSCH transmission occasions.

When one TCI state is indicated in the DCI with the "transmission configuration indication" field, the UE may expect to receive multiple slot-level PDSCH transmission occasions of the same TB using one TCI state across multiple PDSCH transmission occasions.

In addition, in TS 38.331, description is made with respect to RepetitionSchemeConfig IE for the repeated transmission configuration as shown in table 18 below.

TABLE 18

Table 19 illustrates a description of the fields of RepetitionSchemeConfig IE.

TABLE 19

/>

As can be seen from what is described in the standard (e.g., TS 38.214/TS 38.331), two TCI states may be indicated to the UE for repeated PDSCH transmissions. Additionally, each TCI state may correspond to a different resource region (e.g., time resource/frequency resource, etc.) based on the determined rules. Thus, different TRPs corresponding to different TCI states repeatedly transmit PDSCH based on the same Transport Block (TB) using different resource regions, so that time/frequency diversity can be obtained to improve system performance. Meanwhile, it can be considered that the retransmission operation is used in the HST-SFN scene. That is, it can be used to improve system performance by partially modifying existing operations according to the HST-SFN scenario. For example, in a repeated PDSCH transmission operation of Rel-16, the base station may configure/indicate two TCI states to the terminal. After configuring/indicating multiple Transmission Opportunities (TOs), two TCI states may be mapped TO different TOs, respectively. Here, if two TCI states are not mapped TO different TOs, but can be used TO indicate different QCL hypotheses configured with signals of SFN in the same TO, a repeated transmission operation configured with signals of SFN performed based on the two TCI states can be supported. In addition, in the HST-SFN scenario, each QCL hypothesis configured with different signals of the SFN may be indicated, and the signals configured with the SFN are repeatedly transmitted through a plurality of TOs. Based on the repeated transmission technology, the reliability and coverage of PDSCH transmission in the HST-SFN scene can be improved.

Fig. 17 (a) illustrates the existing operation of Rel-16, and fig. 17 (b) illustrates the proposed operation of the present disclosure. In addition, FIG. 18 (a) illustrates the existing operation of Rel-16, and FIG. 18 (b) illustrates the proposed operation of the present disclosure. In addition, FIG. 19 (a) illustrates the existing operation of Rel-16, and FIG. 19 (b) illustrates the proposed operation of the present disclosure.

Meanwhile, the above-described method of repeatedly transmitting signals of SFNs and indicating each QCL hypothesis of signals of different SFNs may also be considered in PDCCH repetition transmission to be discussed in Rel-17. As described in proposal #1 above, the same DCI may be transmitted through a plurality of Monitoring Locations (ML) based on a repetition/partial method. Here, a case where signals transmitted in a plurality of MLs do not correspond to different TCI states, and signals transmitted in each ML are SFN-ed of different signals having different TCI states may be considered. Based on the repeated transmission technology, the reliability and coverage of PDCCH transmission in the HST-SFN scene can be improved.

In this proposal, TO (transmission opportunity)/ML (monitoring location) may refer TO a PDSCH transmission region configured/indicated TO a terminal for repeatedly transmitting PDSCH/a PDCCH transmission region configured/indicated TO a terminal for repeatedly transmitting PDCCH, respectively.

Proposal c#1: the base station may configure/indicate to the terminal whether to operate the SFN. In case of configuring/indicating a terminal for SFN operation, it may be assumed that when configuring/indicating repeated transmission of PDSCH/PDCCH, SFN signals are repeatedly transmitted through a resource region configured/indicated for repeated transmission. Here, different TCI states of the SFN signal to be repeatedly transmitted may be determined based on a plurality of TCI states configured/indicated for repeated PDSCH/PDCCH transmissions.

Four operations were introduced as a PDSCH retransmission method of Rel-16, which corresponds to FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA and slot level retransmission. First, if the case of FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA is described, one of three operations can be configured based on RRC signaling (e.g., "FDM-TDM" in repetitionschemeconfig IE). When DCI scheduling PDSCH indicates two TCI states and DMRS port(s) included in a single CDM group, it may be assumed that PDSCH is actually transmitted based on the above operation. Here, when the proposed method is applied (e.g., the base station configures/indicates TO the terminal whether TO operate the SFN), the terminal may assume that different signals corresponding TO two TCI states indicated through the DCI are transmitted through the SFN through a plurality of TOs scheduled through the DCI.

Fig. 17 shows the difference between the existing operation and the proposed operation under the assumption of the frequency domain retransmission scheme (e.g., FDMSCHEMEA, FDMSCHEMEB), and fig. 18 shows the difference between the existing operation and the proposed operation under the assumption of the time domain retransmission scheme (e.g., the assumption TDMSCHEMEA).

Meanwhile, if the case of slot-level retransmission is described, the number of retransmission RepNumR may be mapped to PDSCH-TimeDomainResourceAllocation corresponding to time domain scheduling information of PDSCH based on RRC signaling (e.g., "Slotbased" in repetitionschemeconfig IE). When DCI scheduling PDSCH indicates two TCI states, DMRS port(s) included in a single CDM group, and time domain resource allocation information TO which RepNumR (e.g., repetitionNumber in PDSCH-TimeDomainResourceAllocation field) is mapped, terminal UE may assume that PDSCH is transmitted based on slot-level retransmission via TO of RepNumR scheduled by DCI. Here, when the proposed method is applied, the terminal may assume that different signals corresponding TO two TCI states indicated through DCI are SFN and transmitted through a plurality of TOs scheduled through DCI. In fig. 19, for repetition and TCI mapping REPTCIMAPPING (i.e., TCIMAPPING), a cyclic mapping CYCMAPPING (i.e., CYCLICMAPPING) is assumed, and for repetition number RepNumR16 (i.e., repetitionNumber), 8 is assumed.

Meanwhile, as proposed in proposal #1, a resource region in which a plurality of PDCCHs corresponding to the same DCI are to be transmitted may be defined. In this case, a plurality of TCI states corresponding to each resource region may be configured/indicated. Here, when applying the proposed method, the terminal may assume that different signals corresponding to different TCI states are repeatedly SFN and transmitted (by repetition/partial) in a plurality of resource regions. For example, two ML and two TCI states for transmitting a plurality of PDCCHs corresponding to the same DCI may be configured/indicated to a terminal, and a different TCI state may be mapped to each ML. In this case, when the proposed method is applied, the terminal can assume that different signals corresponding to two TCI states are SFN and transmitted through two ML.

Fig. 20 (a) illustrates the operation of proposal #1, and fig. 20 (b) illustrates the operation of proposal C # 1. In addition, fig. 21 (a) illustrates the operation of proposal #1, and fig. 21 (b) illustrates the operation of proposal C # 1.

In the following description, more detailed examples of L1/L2 signaling for applying the proposed operations will be described.

Example 1-1) the SFN scheme may be configured by REPTCIMAPPING configured to the terminal for slot-level repeated transmission of PDSCH. In the current standard CYCMAPPING (i.e., CYCLICMAPPING) or SEQMAPPING (i.e., sequentialMapping) may be configured to a terminal through REPTCIMAPPING (i.e., TCIMAPPING). Here, when the CYCMAPPING is configured, different TCI states may be mapped alternately TO different TOs, and when the SEQMAPPING is configured, different TCI states can be mapped in units of two consecutive TOs. By applying this proposal, one of the CYCMAPPING/SEQMAPPING/SFNMAPPING methods can be configured by REPTCIMAPPING. Here, when the SFNMAPPING method is configured, it may be assumed that a different signal corresponding TO each TCI state is configured with an SFN based on a plurality of TCI states configured/indicated TO the terminal and is repeatedly transmitted through a plurality of TO areas allocated TO the terminal.

Examples 1-2) when other conditions than the condition that the DMRS port(s) indicated to the terminal are included in a single CDM group among conditions (e.g., repNum configuration/indication of one or two TCI states, etc.) of PDSCH slot level retransmission are satisfied, and when the DMRS port(s) indicated to the terminal are included in a plurality of CDM groups, it may be assumed that the SFN method is applied. In this case, it may be assumed that DMRS port(s) applied to actual PDSCH transmission are limited to DMRS port(s) included in a specific CDM group. The above example corresponds to a method of configuring/indicating whether to apply the SFN method using the condition undefined in Rel-16. In Rel-16, it is assumed that DMRS port(s) for PDSCH are included in a single CDM group in case of slot-level repeated transmission. Thus, the case included in a plurality of CDM groups may be regarded as an error case in Rel-16, and this may be used to indicate the above-proposed operation. However, when multiple CDM groups are indicated, there is a constraint that at least 2 layers should be scheduled. As a method for solving the constraint, it may be assumed that only DMRS port(s) included in a specific CDM group among the indicated CDM groups are applied to actual PDSCH transmission. As an example of a specific CDM group, it may be defined as a fixed rule, such as a CDM group including/corresponding to a first port of DMRS port(s) indicated by DCI, or a lowest/highest indexed CDM group. Alternatively, a specific CDM group may be configured/indicated to a terminal based on L1/L2 signaling.

Example 2-1) may define parameters that enable configuration of the SFN method separately from RepSchemeEnabler, repSchemeEnabler being RRC parameters for configuring a specific scheme in FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA. Additionally, based on the defined parameters, it may be configured/indicated whether to operate the SFN. Here, if the condition FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA is satisfied and the SFN method is configured, the terminal can assume that a different signal corresponding TO each TCI state is configured with the SFN and repeatedly transmitted based on the plurality of TCI states configured/indicated TO the terminal by the plurality of TO assigned TO the terminal based on the FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA scheme. For example, the parameters for configuring/indicating whether to operate the SFN may be parameters that may be additionally configured only to a specific scheme. For example, when a terminal is configured TDMSCHEMEA, it may be a parameter that may be otherwise configured for the terminal. This is because the signal configured with the SFN can be used for the purpose of improving the coverage by increasing the total energy of the transmission signal via repeated transmission in the time domain.

Example 2-2) new options for configuring the repeated transmission scheme based on SFN can be added RepSchemeEnabler, repSchemeEnabler to the RRC parameters for configuring a specific scheme in FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA. Alternatively, the SFN-based retransmission scheme may be configured by a separate RRC parameter different from RepSchemeEnabler. In this case, multiple TO's can be defined based on the particular scheme in FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA. For example, a specific scheme in FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA/FDMSchemeB-SFN/TDMS CHEMEA-SFN may be configured for a terminal through RepSchemeEnabler. When FDMSchemeB-SFN is configured, multiple TOs can be defined based on FDMSchemeB scheme. When TDMSCHEMEA-SFN is configured, multiple TOs can be defined based on TDMSCHEMEA scheme. In addition, when the condition FDMSchemeB/TDMSCHEMEA is satisfied, the terminal can assume that different signals corresponding TO each TCI state are configured with SFN and repeatedly transmitted based on a plurality of TCI states configured/indicated TO the terminal by a plurality of TO allocated TO the terminal based on the FDMSchemeB/TDMSCHEMEA scheme. Alternatively, after newly defining a parameter called RepSchemeEnabler-SFN, a specific one of the repeated transmission schemes based on SFN (e.g., FDMSchemeB-SFN/TDMSCHEMEA-SFN) can be configured for the terminal through the parameter. In this case RepSchemeEnabler as a parameter of Rel-16 and the newly proposed RepSchemeEnabler-SFN may have mutually exclusive properties. In the proposed operation, the definition or operating conditions for TO may be the same as in example 2-1 above.

Example 2-3) when other conditions than the condition that the DMRS port(s) indicated to the terminal are included in a single CDM group among the conditions for FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA transmission scheme are satisfied, and when the DMRS port indicated to the terminal is included in a plurality of CDM groups, as described in various examples of proposal c#1 (e.g., example 1-1/1-2/2-1/2-2, etc.), the terminal may assume that one indication method and SFN method among FDMSCHEMEA/FDMSchemeB/TDMSCHEMEA are combined and applied.

Meanwhile, in the above example, when a plurality of TCI states and a plurality of TOs are configured/indicated TO a terminal by using the Rel-16 operation, it is assumed that different signals corresponding TO each TCI state are configured with SFNs based on the plurality of TCI states configured/indicated TO the terminal and are repeatedly transmitted through the plurality of TO areas allocated TO the terminal. Here, cases other than the duplicate transmission described in proposal #1 may also be considered (together). In addition, for this purpose, the following methods other than those described in proposal #1 may also be considered.

Example 3) i) when RRC parameters related to the number of repeated transmissions of slot level repeated transmission of PDSCH are not configured to the terminal (i.e., all entries in TDRA field do not include RepNumR), ii) when the number of repeated transmissions is not indicated to be 2 or more (i.e., even though at least one entry in TDRA field includes RepNumR, when TDRA field of DCI, repNum16 value is not indicated to be 2 or more), and/or iii) if RepSchemeEnabler, which is an RRC parameter for configuring a specific transmission method, is not configured, when a plurality of TCI states are indicated to the terminal and the indicated DMRS port(s) is included in a single CDM group, it may be assumed that different signals corresponding to each TCI state are configured with SFN and transmitted through a resource region allocated to the terminal. Example 3 above corresponds to a method of configuring/indicating whether to apply the SFN method using the condition undefined in Rel-16. The above method differs from the previous examples 1-1/1-2/2-1/2-2/2-3 in that it does not assume multiple TOs. That is, the SFN-enabled signal may be transmitted through a resource region allocated through DCI that does not schedule repeated transmission. However, if slot level PDSCH repeated transmission is configured through RRC parameters in Rel-15 (i.e., when PDSCH-AggregationFactor is set to 2 or more), when SNF is enabled according to the above proposal, PDSCH may be transmitted through an SFN having a TCI state indicated in each slot during multiple slots in which PDSCH is repeatedly transmitted.

Table 20 below illustrates examples of dynamic/semi-static configurations for switching/disabling/enabling between MTRP/STRP transmission schemes supported by existing Rel-16 and the proposed methods of the present disclosure. All rows from index 0 to G correspond to the conditions agreed in Rel-16, and H1, H2, and H3 correspond to examples of signaling conditions proposed by the present disclosure for indicating an SFN transmission scheme.

H1 corresponds to example 3, and H2 shows the case of indicating with URLLCSchemeEnabler (i.e., repSchemeEnabler) as in example 2-2 whether or not to transmit over the SFN. In addition, when the number of CDM groups through which DMRS ports are transmitted in the SFN is 2 in order to distinguish it from the condition d″ of the 1a/NCJT (a method in which two TRPs transmit DMRS port(s) belonging to two different CDM groups, respectively), H3 shows that if the SFN technology is configured with URLLCSchemeEnabler (i.e., repSchemeEnabler), the SFN configuration takes precedence over the 1a/NCJT and performs transmission in the SFN method, unlike d″.

TABLE 20

In table 20, condition 1 is a condition indicating one entry in pdsch-TimeDomainAllocationList including URLLCRepNum (i.e., > 1) in TDRA through DCI. Condition 2 is a condition that one entry of pdsch-TimeDomainAllocationList having no URLLCRepNum is indicated by DCI but at least one entry having URLLCRepNum is indicated. Condition 4 is a condition that no entry of URLLCRepNum is included in TDRA.

The method proposed by proposal #1 below can be applied independently (for example, the method may be performed by a method of, for example, a proposal A#1/proposal A#1-1-1/proposal A#1-2/proposal A#2-1-1/proposal A#2-1-2/proposal A#2-2-1/proposal A#2-3-1/proposal A#2-4-1/proposal A#2-4-2/proposal A#3/proposal A#4/proposal A#5-1/proposal A#5-2/proposal A#5-3-1/proposal A#5-3-2/proposal A#5-3-3, etc.), and a method proposed by following#2 (for example, proposal b#1/proposal b#1-1/proposal b#1-2, etc.) and the method proposed by the following proposal #3 (for example, proposal c#1). However, the present disclosure is not limited to use alone, and one or more of the proposed methods may be considered and applied together. For example, in the methods presented below proposal #1, the method for configuring/indicating the SFN scheme may also be used as a method for the base station to configure/indicate the SFN scheme to the terminal in proposal # 2. Here, the plurality of QCL RSs configured/indicated to the terminal may correspond to DMRS port(s) of different CDM groups, respectively.

In addition, when performing the SFN transmission set forth above, constraints may be defined to operate only under a certain number of layers (e.g., 1 layer). This is because, for example, when SFN transmission is supported for two or more layers, performance degradation may occur due to the influence of interlayer interference.

In addition, although the case of indicating 2 TCI states is mainly described above, it is not limited to the case of 2 TCI states. The proposed method may also be applied to multiple TCI states of 2 or more TCI states. Here, for example, when the number of TCI states indicated to the terminal is three or more, the proposed operation (SFN transmission/SFN-based retransmission) may be applied to compare with the Rel-16 operation.

Meanwhile, in the above description, "SFN transmission" refers to a method in which a plurality of RSs (/ antenna ports) are indicated/configured/assumed as QCL references of the same QCL parameters for a single antenna port.

The DMRS port(s) of the antenna port field of the DCI in the proposed method (e.g., proposal # 1/proposal # 2/proposal # 3) and each proposed sub-proposed method may be determined/indicated, and the antenna port(s) may be determined according to the indicated order of the DMRS port(s). Further, CDM groups corresponding to the determined antenna port(s) may be determined. In addition, data may be transmitted/received based on the antenna port(s).

FIG. 22 illustrates an example of signaling between a network and a UE to which the proposed method may be applied (e.g., propozone A#1/Propozone A#1-1-1/Propozone A#1-2/Propozone A#2-1-1/Propozone A#2-1-2/Propozone A#2-1/Propozone A#2-3-1/Propozone A#2-4-1/Propozone A#2-4-2/Propozone A#3/Propozone A#4/Propozone A#5-1/Propozone A#5-2/Propozone A#5-3-1/Propozone A#5-3-2/Propozone A#5-3-2/Propozone A#1-1/Propozone A#2-1-3/pozone B#1-1/Propozone B#1, etc.). Here, the UE/network may be an example and may be replaced with various devices as described in fig. 25 and 26. Fig. 22 is merely for convenience of description and does not limit the scope of the present disclosure. In addition, depending on the situation and/or configuration, some steps shown in fig. 22 may be omitted. In addition, the above-described technical contents (e.g., HST-SFN arrangement/M-TRP related operation, etc.) may be referred to/used in the operation of the network/UE of fig. 22.

In the following description, the network may be one base station including a plurality of TRPs, and may be one cell including a plurality of TRPs. Alternatively, the network may comprise a plurality of Remote Radio Heads (RRHs)/Remote Radio Units (RRUs). As an example, an ideal/non-ideal backhaul may be configured between TRP 1 and TRP 2 included in the network. In addition, the following description will be described based on a plurality of TRPs, but this can be equally extended and applied to transmission through a plurality of panels/cells, and can also be extended and applied to transmission through a plurality of RRHs/RRUs.

In addition, as described above, the "TRP" may be applied by being replaced with terms such as a panel, an antenna array, a cell (e.g., macrocell/microcell/picocell, etc.), TP (transmission point), base station (gNB, etc.). As described above, TRPs may be classified according to information (e.g., index, ID) about CORESET groups (or CORESET pools). As an example, when one terminal is configured to perform transmission/reception with a plurality of TRPs (or cells), this may mean configuring a plurality of CORESET groups (or CORESET pools) for one terminal. This CORESET group (or CORESET pool) configuration may be performed by higher layer signaling (e.g., RRC signaling, etc.). In addition, a base station may refer to a general term for an object for transmitting and receiving data using a terminal. For example, a base station may be a concept including one or more TPs (transmission points), one or more TRPs (transmission and reception points), and the like. Further, the TP and/or TRP may include a panel of a base station, a transmission and reception unit, and the like.

Although not shown in fig. 22, the UE and/or the network may perform a Channel State Information (CSI) related procedure. For example, the UE and/or the network may be configured to perform the CSI-related process described above. In particular, the above-described CSI measurement and CSI reporting processes may be performed between UEs and/or networks. For example, based on information obtained through the CSI-related process, configuration related to an operation to be described later/an operation to be described later may be performed.

In addition, although not shown in fig. 22, the UE may transmit UE capability information to the network. UE capability information may include information as set forth above (e.g., capability information of the operation related UE described in Programming A#1/Programming A#1-1-1/Programming A#1-2/Programming A#2-1-1/Programming A#2-1-2/Programming A#2-2-1/Programming A#2-3/Programming A#2-4-1/Programming A#2-4-2/Programming A#3/Programming A#4/Programming A#5-1/Programming A#5-2/Programming A#5-3-1/Programming A#5-3-3/Programming A#5-1/Programming B#1/Programming A#1-1/Programming A#2-3/etc.

The UE may receive configuration information from the network (S2201). The configuration information may include System Information (SI) and/or scheduling information and/or configuration information related to Beam Management (BM), etc. For example, the configuration information may include information related to network configuration (i.e., TRP configuration), resource allocation related to multiple TRP-based transmissions and receptions, and so on.

For example, based on the proposed method described above (e.g., subtraction A#1/Subtraction A#1-1-1/Subtraction A#1-2/Subtraction A#2-1-1/Subtraction A#2-1-2/Subtraction A#2-2-1/Subtraction A#2-3-1/Subtraction A#2-4) 1/Provisioning A#2-4-2/Provisioning A#3/Provisioning A#4/Provisioning A#5-1/Provisioning A#5-2/Provisioning A#5-3-1/Provisioning A#5-3-3/Provisioning A#5-3/Provisioning B#1-1/Provisioning B#1-2/Provisioning C#1, etc.), the configuration information may include information regarding whether to operate the SFN (e.g., whether to operate the HST-SFN) and/or whether to configure multiple ML and/or TCI state(s) and/or QCL RS(s) and/or DMRS port(s). For example, whether to perform SFN operation or whether to perform transmission/reception operation based on a plurality of ML may be indicated based on the configuration information. For example, whether to configure to perform SFN operation for a particular code point for TCI state may be configured based on the configuration information. For example, multiple (different) TCI states may be configured for DMRS port(s) associated with a control channel (e.g., PDCCH) based on the configuration information. For example, the configuration information may include configuration for CORESET/CORESET groups and/or SS configuration. Here, the configuration for CORESET may include information related to the QCL RS/TCI state. In addition, the SS configuration including CORESET configurations may include information related to the additional QCL RS/TCI states. For example, the SFN transmission scheme and/or the ML-based repetition/partial transmission scheme may be determined/configured based on the number of QCL RS/TCI states (or conversely, the number of QCL RS/TCI states may be determined based on the SFN transmission scheme and/or the ML-based repetition/partial transmission scheme). For example, the activation/deactivation of multiple TCI states configured and/or TCI states added to a particular CORESET may be configured based on configuration information. For example, a TCI state combination candidate, which may be composed of a plurality of TCI states, may be configured based on the configuration information. In addition, the configuration information may include information about TCI state combinations.

For example, whether to perform SFN operation, as described in proposal C #1 of proposal #3, may be configured using higher layer parameters (e.g., REPTCIMAPPING/RepSchemeEnabler). For example, the configuration information may include new parameters for configuring whether to perform SFN operation.

The configuration information may be transmitted through a higher layer (e.g., RRC or MAC CE). In addition, when the configuration information is predefined or configured, the corresponding steps may be omitted.

The operation of the above-described step S2201 in which the UE (100/200 in fig. 25 and 26) receives configuration information from the network (100/200 in fig. 25) may be implemented by the devices of fig. 25 and 26 described below, for example. For example, referring to fig. 25, the one or more processors 102 may control the one or more transceivers 106 and/or the one or more memories 104 to receive the configuration information, and the one or more transceivers 106 may receive the configuration information from the network.

The UE may receive control information from the network (S2202). The control information may be received through a control channel (e.g., PDCCH). For example, the control information may be DCI. For example, based on the proposed method described above (e.g., subtraction A#1/Subtraction A#1-1-1/Subtraction A#1-2/Subtraction A#2-1-1/Subtraction A#2-1-2/Subtraction A#2-2-1/Subtraction A#2-3-1/Subtraction A#2-4) 1/Provisioning A#2-4-2/Provisioning A#3/Provisioning A#4/Provisioning A#5-1/Provisioning A#5-2/Provisioning A#5-3-1/Provisioning A#5-3-3/Provisioning A#5-3/Provisioning B#1-1/Provisioning B#1-2/Provisioning C#1, etc.), the control information is information regarding whether to perform SFN operation (e.g., whether to perform HST-SFN operation) and/or TCI state(s) and/or QCL RS(s) and/or DMRS port(s) and/or ML related resource information and/or antenna port field. For example, multiple (different) TCI states may be indicated/configured in a TCI state field in control information (e.g., DCI). For example, the control information may include information about antenna port-to-layer mapping, and as described in proposal b#1/proposal b#1-1/proposal b#1-2 of proposal 2 above, an antenna port-to-layer mapping relationship/the number of transport layers, etc. may be determined/configured.

For example, as described in proposal c#1 of proposal#3, the slot-level repeated transmission configuration is configured by the configuration information, but when DMRS ports configured based on the control information are included in/correspond to a plurality of CDM groups, SFN operation may be configured.

For example, based on the information configured/indicated in step S2201, the UE may perform channel estimation/compensation and may receive control information. For example, based on the proposed method described above (e.g., proposed A#1/proposed A#1-1-1/proposed A#1-2/proposed A#2-1-1/proposed A#2-1-2/proposed A#2-2-1/proposed A#2-3-1/proposed A#2-4-2/proposed A#3/proposed A#4/proposed A#5-1/proposed A#5-2/proposed A#5-3-1/proposed A#5-3-2/proposed A#5-3-3/proposed A#1/proposed B#1-1/proposed B#1-2/proposed C#1, etc.), the UE may assume transmission and may perform channel estimation (e.g., PDCCH) based on the QCS I state corresponding to the QCS.

For example, the ML-related resource information included in the control information may include resource region (ML) information of PDCCHs corresponding to the same DCI. For example, multiple resource regions (e.g., ML) may be configured/defined, and each resource region may correspond to a different QCL RS (s)/(TCI state (s)/TRP. For example, each of the plurality of QCL RSs (/ TCI states) may sequentially correspond to each of the plurality of resource areas (ML). For example, a control channel (e.g., PDCCH) may be received/transmitted over repetitions/portions based on multiple resource regions. For example, a control channel (e.g., PDCCH) may be received/transmitted by repetition/portion based on a plurality of resource regions, and SFN transmission may be performed in each resource region (e.g., a control channel is received/transmitted based on a plurality of QCL reference signals (/ antenna ports) of the same QCL parameters for a single antenna port).

For example, a CRC of control information (e.g., DCI) may be scrambled based on the SFN-RNTI, and a UE receiving it may assume that data (/ PDSCH) scheduled based on the control information is based on SFN transmission.

For example, the operation of the UE (100/200 in fig. 25 and 26) of the above-described step S2202 to receive control information from the network (100/200 in fig. 25) may be implemented by the apparatus of fig. 25 and 26 described below. For example, referring to fig. 25, the one or more processors 102 may control the one or more transceivers 106 and/or the one or more memories 104 to receive control information, and the one or more transceivers 106 may receive control information from the network side.

The UE may receive data from the network (S2203). Data may be received through a data channel (e.g., PDSCH). For example, the data may be scheduled based on the control information. In addition, data may be received based on the information configured/indicated in step S2201/S2202. For example, based on the information configured/indicated in step S2201/S2202, the UE may perform channel estimation/compensation and receive data. For example, based on the proposed method described above (e.g., proposed A#1/proposed A#1-1-1/proposed A#1-2/proposed A#2-1-1/proposed A#2-1-2/proposed A#2-2-1/proposed A#2-3-1/proposed A#2-4-2/proposed A#3/proposed A#4/proposed A#5-1/proposed A#5-2/proposed A#5-3-1/proposed A#5-3-2/proposed A#5-3-3/proposed A#1/proposed B#1-1/proposed B#2/proposed C#etc.), the UE may assume the transmission and may perform channel estimation/compensation based on the QCS status corresponding to the TCI. For example, when a plurality of (different) TCI states are indicated/configured in a TCI state field in control information (e.g., DCI), assuming that the DMRS port is configured with SFNs based on the plurality of TCI states, channel estimation/compensation may be performed based on QCL RSs corresponding to each TCI state.

For example, as described in the above proposal a#5/proposal a#5-1/proposal a#5-2/proposal a#5-3-1/proposal a#5-3-2/proposal a#5-3-3, the QCL RS/TCI state applied when receiving the data channel may be determined based on an offset value between control information (e.g., DCI) and a data channel (e.g., PDSCH) scheduled based on the control information. For example, if the offset value is greater than a particular threshold and no TCI information is present in the control information, QCL RS/TCI states associated with SFN transmission/multiple ML based transmission may also be applied to the data channel. For example, if the offset value is greater than a certain threshold and TCI information is not present in the control information, a certain QCL RS/TCI state (e.g., related resource location/index/QCL RS based on SS configuration, etc.) may be applied to the data channel, and in this case, may be identified as a single TRP operation. For example, if the offset value is greater than a certain threshold and TCI information is not present in the control information, it may be identified that a data channel (e.g., PDSCH) is received based on one of M-TRP transmission, S-TRP transmission, and SFN transmission.

For example, as described in proposal c#1 of proposal#3, a UE configured/indicated for SFN operation may assume that when PDSCH/PDCCH retransmission is configured/indicated, a signal configured with SFN is repeatedly transmitted through a resource region configured/indicated for retransmission.

For example, the data may refer to a TB or information/channel (e.g., PDSCH) encoded from the TB. For example, based on the proposed method described above (e.g., subtraction A#1/Subtraction A#1-1-1/Subtraction A#1-2/Subtraction A#2-1-1/Subtraction A#2-1-2/Subtraction A#2-2-1/Subtraction A#2-3-1/Subtraction A#2-4) 1/Provisioning A#2-4-2/Provisioning A#3/Provisioning A#4/Provisioning A#5-1/Provisioning A#5-2/Provisioning A#5-3-1/Provisioning A#5-3-3/Provisioning A#5-3/Provisioning B#1-1/Provisioning B#1-2/Provisioning C#1, etc.), the size of TB may be calculated. When the UE calculates the size of the TB, the contents described in the above TBs determination may be used/referred to.

For example, the operation of the UE (100/200 in fig. 25 and 26) of the above-described step S2203 to receive data from the network (100/200 in fig. 25) may be implemented by the apparatus of fig. 25 and 26 described below. For example, referring to fig. 25, one or more processors 102 may control one or more transceivers 106 and/or one or more memories 104 to receive data, and one or more transceivers 106 may receive data from a network.

As mentioned above, the above-described network/UE signaling and operations (e.g., proposal A#1/proposal A#1-1-1/proposal A#1-2/proposal A#2-1-1/proposal A#2-1-2-Provisioning A#2-2/Provisioning A#2-2-1/Provisioning A#2-3-1/Provisioning A#2-4-2/Provisioning A#3/proposal A#4/proposal A#5-1/proposal A#5-2/proposal A#5-3-1/proposal A#5-3-2/proposal A#5-3-3/proposal B#1-1/proposal B#1-2/proposal C#1/FIG. 22, etc.) can be realized by the following devices (for example, FIGS. 25 and 26). For example, the network (TRP 1/TRP 2) may correspond to a first wireless device, the UE may correspond to a second wireless device, and vice versa may be considered in some cases.

Such as the network/UE signaling and operations described above (e.g., subtraction A#1/Subtraction A#1-1-1/Subtraction A#1-2/Subtraction A#2-1-1/Subtraction A#2-1-2/Subtraction A#2-2-1/Subtraction A#2-3-1/Subtraction A#2-4-1/Subtraction A#2-4-2/Subtraction A#3) the/Provisioning A#4/Provisioning A#5-1/Provisioning A#5-2/Provisioning A#5-3-1/Provisioning A#5-3-2/Provisioning A#5-3-3/Provisioning B#1-1/Provisioning B#1-2/Provisioning C#1/FIG. 22, etc.) may be performed by one or more of the processors of FIGS. 25 and 26 (e.g., 102, 202), and the network/UE signaling and operations described above (e.g., the instructions/procedure (e.g., as follows: programming A#1/Programming A#1-1-1/Programming A#1-2/Programming A#2-1-1/Programming A#2-2-1/Programming A#2-3/Programming A#2-4-1/Programming A#2-4-2/Programming A#3/Programming A#4/Programming A#5-1/Programming A#5-2/Programming A#5-3-1/Programming A#5-3-3/Programming A#5-3/Programming B#1/Programming A#1-1/Programming B#1-2-1/Programming A#2-1/,. C#1/figure 22, etc.), instructions, executable code) are stored in one or more memories (e.g., 103, 204 of fig. 25) for at least driving at least one processor (e.g., 102, 202) of fig. 25 and 26.

FIG. 23 illustrates operations of a terminal based on the proposed method (e.g., programming A#1/Programming A#1-1/Programming A#1-2/Programming A#2-1-1/Programming A#2-1-2/Programming A#2-2-1/Programming A#2-3-1/Programming A#2-4-2/Programming A#3/Programming A#4/Programming A#5-1/Programming A#5-2/Programming A#5-3-1/Programming A#5-3-2/Programming A#5-3-3/Programming A#5-3/Programming A#1-3/Programming B#1/Programming A#1-1/Programming B#1-2/Programming C#1, etc.). The example of fig. 23 is for ease of description and does not limit the scope of the present disclosure. Some steps shown in fig. 23 may be omitted depending on the circumstances and/or configuration. In addition, the terminal in fig. 23 is only one example, and may be implemented as the devices shown in fig. 25 and 26 below. For example, the processor 102/202 of fig. 25 may control to transmit/receive channels/signals/data/information using the transceiver 106/206 and control to store the transmitted or received channels/signals/data/information in the memory 104/204.

Additionally, the operations of fig. 23 may be processed by the one or more processors 102, 202 of fig. 25, and the operations of fig. 23 may be stored in a memory (e.g., the one or more memories (103, 204) of fig. 25) in the form of instructions/programs (e.g., instructions, executable code) for driving the at least one processor (e.g., 102, 202) of fig. 25.

Referring to fig. 23, the terminal receives configuration information related to CORESET and/or related to a search Space Set (SS) from a base station (S2301).

Here, the configuration information (e.g., the configuration information related to CORESET) may include TCI state information related to CORESET. Alternatively, the configuration information (e.g., SS-related configuration information) may include an identifier of CORESET associated in the configuration information, and the configuration information for CORESET identified by the identifier of the corresponding CORESET may include TCI status information related to the CORESET.

Here, the TCI state information includes information about one or more reference signals in a quasi co-located (QCL) relationship with one or more antenna ports of the DMRS of the PDCCH.

Here, since information on a plurality of TCI states is included in the configuration information, a plurality of TCI states may be configured for CORESET (i.e., CORESET for the terminal to receive/monitor the PDCCH).

In addition, since each of the first configuration information related to CORESET and the second configuration information related to the search space set includes information about one or more TCI states, a plurality of TCI states for CORESET may be configured. In this case, if the second configuration information includes information on the plurality of TCI states, the plurality of TCI states included in the second configuration information may be preferentially configured in CORESET (i.e., the information on the TCI states in the first configuration information may be ignored).

The terminal may receive a MAC CE related to the TCI state from the base station (S2302).

Here, the configuration information of step S2301 includes a plurality of TCI state candidates for CORESET (i.e., CORESET used by the terminal to receive/monitor the PDCCH), and a plurality of TCI states among the plurality of TCI state candidates are indicated by the MAC CE of step S2302, so that the plurality of TCI states can be configured for CORESET.

In addition, the configuration information of step S2301 includes a plurality of TCI state candidates for CORESET (i.e., CORESET for terminal to receive/monitor PDCCH), and after one TCI state among the plurality of TCI state candidates is configured by the first MAC CE in step S2302, activation of an additional TCI state is indicated by another second MAC CE in step S2302 so that a plurality of TCI states can be configured for CORESET.

In addition, the configuration information of step S2301 includes information on a TCI state combination candidate that may be composed of a plurality of TCI states for CORESET (i.e., CORESET for terminal to receive/monitor PDCCH), and the plurality of TCI states may be configured for CORESET by indicating a specific TCI state combination among the TCI state combination candidates by the MAC CE in step S2302.

As described above, a plurality of TCI states for the respective CORESET (i.e., CORESET used by the terminal to receive/monitor the PDCCH) only through configuration information for CORESET and/or configuration information for the SS may be configured. In this case, step S2302 may be omitted.

The terminal receives a PDCCH from the base station (S2303). That is, the terminal receives DCI from the base station through the PDCCH.

Here, the terminal may receive a PDCCH on the configured SS and/or CORESET.

Here, based on the plurality of TCI states configured in CORESET according to the above steps S2301 and/or S2302, the terminal may assume one or more antenna ports of the DMRS transmitting the PDCCH through the SFN based on the plurality of TCI states. In this case, the terminal may perform channel estimation and/or channel compensation on the PDCCH based on each channel value corresponding to reference signals of a plurality of TCI states. In addition, it may be assumed that PDSCH scheduled by PDCCH is also transmitted through SFN.

In addition, for the same DCI, the terminal may repeatedly receive the PDCCH at a plurality of transmission occasions. In this case, each transmission occasion of the PDCCH may correspond to a different TCI state among a plurality of DCI states configured in CORESET related to the PDCCH.

Although not depicted in fig. 23, according to the proposed method of the present disclosure described above (e.g., proposal A#1/proposal A#1-1-1/proposal A#1-2/proposal A#2-1-1/proposal A#2-1-2/Provisioning A#2-2-1/Provisioning A#2-3-1/Provisioning A#2-4-2/Provisioning A#3/Provisioning A#4/Provisioning A#5-1/Provisioning A#5-2/Provisioning A#5-3-1/Provisioning A#5-3-2/Provisioning A#5-3-3/Provisioning B#1-1/Provisioning B#1-2/Provisioning C#1, etc.) may be performed together with the operation of the terminal of FIG. 23.

FIG. 24 illustrates operations of a terminal based on the proposed method (e.g., programming A#1/Programming A#1-1/Programming A#1-2/Programming A#2-1-1/Programming A#2-1-2/Programming A#2-2-1/Programming A#2-3-1/Programming A#2-4-2/Programming A#3/Programming A#4/Programming A#5-1/Programming A#5-2/Programming A#5-3-1/Programming A#5-3-2/Programming A#5-3-3/Programming A#5-3/Programming A#1-3/Programming B#1/Programming A#1-1/Programming B#1-2/Programming C#1, etc.). The example of fig. 24 is for ease of description and does not limit the scope of the present disclosure. Some steps shown in fig. 24 may be omitted, depending on the circumstances and/or configuration. In addition, the base station in fig. 24 is only one example, and may be implemented as the devices shown in fig. 25 and 26 below. For example, the processor 102/202 of fig. 25 may control to transmit/receive channels/signals/data/information using the transceiver 106/206 and control to store the transmitted or received channels/signals/data/information in the memory 104/204.

Referring to fig. 24, the base station transmits to the terminal configuration information related to CORESET and/or related to a search Space Set (SS) (S2401).

Here, the configuration information (e.g., the configuration information related to CORESET) may include TCI state information related to CORESET. Alternatively, the configuration information (e.g., SS-related configuration information) may include an identifier of CORESET associated in the configuration information, and the configuration information for CORESET identified by the identifier of the corresponding CORESET may include TCI state information associated with the CORESET.

Here, since information on a plurality of TCI states is included in the configuration information, a plurality of TCI states may be configured for CORESET (i.e., CORESET used by the terminal to receive/monitor the PDCCH).

The base station may transmit a MAC CE related to the TCI state to the terminal (S2402).

Here, the configuration information of step S2401 includes a plurality of TCI state candidates for CORESET (i.e., CORESET used by the terminal to receive/monitor the PDCCH), and a plurality of TCI states among the plurality of TCI state candidates are indicated by the MAC CE of step S2402, so that the plurality of TCI states can be configured for CORESET.

In addition, the configuration information of step S2401 includes a plurality of TCI state candidates for CORESET (i.e., CORESET used by the terminal to receive/monitor the PDCCH), and after one TCI state among the plurality of TCI state candidates is configured by the first MAC CE in step S2402, activation of an additional TCI state is indicated by another second MAC CE in step S2402 so that a plurality of TCI states can be configured for CORESET.

In addition, the configuration information of step S2401 includes information on a TCI state combination candidate that may be composed of a plurality of TCI states for CORESET (i.e., CORESET used by the terminal to receive/monitor the PDCCH), and the plurality of TCI states may be configured for CORESET by indicating a specific TCI state combination among the TCI state combination candidates by the MAC CE in step S2402.

As described above, a plurality of TCI states for the respective CORESET (i.e., CORESET used by the terminal to receive/monitor the PDCCH) only through configuration information for CORESET and/or configuration information for the SS may be configured. In this case, step S2402 may be omitted.

The base station transmits the PDCCH to the terminal (S2403). That is, the base station transmits DCI to the terminal through the PDCCH.

Here, the base station may transmit the PDCCH on the SS and/or CORESET configured to the terminal.

Here, based on the plurality of TCI states configured in CORESET according to steps S2401 and/or S2402 described above, the terminal may assume one or more antenna ports of the DMRS transmitting the PDCCH through the SFN based on the plurality of TCI states. In this case, the terminal may perform channel estimation and/or channel compensation on the PDCCH based on each channel value corresponding to reference signals of a plurality of TCI states. In addition, it may be assumed that PDSCH scheduled by PDCCH is also transmitted through SFN.

Although not depicted in FIG. 24, the proposed method according to the present disclosure described above (e.g., propozone A#1/Propozone A#1-1-1/Propozone A#1-2/Propozone A#2-1-1/Propozone A#2-1-2/Propozone A#2-2-1/Propozone A#2-3-1/Propozone A#2-4-1/Propozone A#2-4-2/Propozone A#3/Propozone A#4/Propozone A#5-1/Propozone A#5-2/Propozone A#5-3-1/Apozone#5-3-2/pozone A#5-3-3/pozone A#1-3/pozone B#1-1/pozone B#1-2/C#1, etc.) may be performed with the operations of the base station of FIG. 24.

General purpose device to which the present disclosure may be applied

Fig. 25 is a diagram illustrating a block diagram of a wireless communication device according to an embodiment of the present disclosure.

Referring to fig. 25, the first wireless device 100 and the second wireless device 200 may transmit and receive wireless signals through a plurality of radio access technologies (e.g., LTE, NR).

The first wireless device 100 may include one or more processors 102 and one or more memories 104, and may additionally include one or more transceivers 106 and/or one or more antennas 108. The processor 102 may control the memory 104 and/or the transceiver 106 and may be configured to implement the descriptions, functions, processes, suggestions, methods, and/or operational flowcharts disclosed in this disclosure. For example, the processor 102 may transmit a wireless signal including the first information/signal through the transceiver 106 after generating the first information/signal by processing the information in the memory 104. Further, the processor 102 may receive a wireless signal including the second information/signal through the transceiver 106, and then store information obtained through signal processing of the second information/signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including commands for executing all or part of the processes controlled by the processor 102 or for executing descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed in this disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem/circuit/chip designed to implement wireless communication technologies (e.g., LTE, NR). The transceiver 106 may be coupled to the processor 102 and may transmit and/or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and/or a receiver. The transceiver 106 may be used with an RF (radio frequency) unit. In this disclosure, a wireless device may mean a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202 and one or more memories 204, and may additionally include one or more transceivers 206 and/or one or more antennas 208. The processor 202 may control the memory 204 and/or the transceiver 206 and may be configured to implement the descriptions, functions, processes, suggestions, methods, and/or operational flowcharts disclosed in this disclosure. For example, the processor 202 may generate the third information/signal by processing the information in the memory 204 and then transmit a wireless signal including the third information/signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information/signals through the transceiver 206, and then store information obtained through signal processing of the fourth information/signals in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, memory 204 may store software code including commands for executing all or part of the processes controlled by processor 202 or for executing descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed in this disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem/circuit/chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 206 may be coupled to the processor 202 and may transmit and/or receive wireless signals via one or more antennas 208. The transceiver 206 may include a transmitter and/or a receiver. The transceiver 206 may be used with an RF unit. In this disclosure, a wireless device may mean a communication modem/circuit/chip.

Hereinafter, the hardware elements of the wireless device 100, 200 will be described in more detail. It is not limited thereto and one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). The one or more processors 102, 202 may generate one or more PDUs (protocol data units) and/or one or more SDUs (service data units) according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts included in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information in accordance with the descriptions, functions, procedures, proposals, methods, and/or operational flow diagrams disclosed in this disclosure. The one or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information to provide to the one or more transceivers 106, 206 according to the functions, procedures, proposals, and/or methods disclosed in the present disclosure. The one or more processors 102, 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure.

One or more of the processors 102, 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more of the processors 102, 202 may be implemented in hardware, firmware, software, or a combination thereof. In an example, one or more ASICs (application specific integrated circuits), one or more DSPs (digital signal processors), one or more DSPDs (digital signal processing devices), one or more PLDs (programmable logic devices), or one or more FPGAs (field programmable gate arrays) may be included in the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure may be implemented by using firmware or software and the firmware or software may be implemented to include modules, procedures, functions, and the like. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed in this disclosure may be included in one or more processors 102, 202 or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present invention may be implemented in firmware or software in the form of codes, commands and/or command sets.

The one or more memories 104, 204 may be coupled to the one or more processors 102, 202 and may be capable of storing data, signals, messages, information, programs, code, instructions, and/or commands in a variety of forms. One or more of the memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drives, registers, cash memory, computer-readable storage medium, and/or combinations thereof. The one or more memories 104, 204 may be located internal and/or external to the one or more processors 102, 202. Further, the one or more memories 104, 204 may be connected to the one or more processors 102, 202 by a variety of techniques, such as a wired or wireless connection.

One or more transceivers 106, 206 may transmit user data, control information, wireless signals/channels, etc. referred to in the methods and/or operational flowcharts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals/channels, etc. referred to in the description, functions, procedures, proposals, methods, and/or operational flowcharts, etc. disclosed in this disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may transmit and receive wireless signals. For example, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Further, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. Further, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, wireless signals/channels, etc. mentioned in the description, functions, procedures, proposals, methods, and/or operational flowcharts, etc. of the present disclosure through one or more antennas 108, 208. In the present invention, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 may process the received user data, control information, wireless signals/channels, etc. by converting the received wireless signals/channels, etc. from RF band signals to baseband signals using the one or more processors 102, 202. The one or more transceivers 106, 206 may convert user data, control information, wireless signals/channels, etc., processed by using the one or more processors 102, 202 from baseband signals to RF band signals. Thus, one or more transceivers 106, 206 may include (analog) oscillators and/or filters.

Referring to fig. 26, the vehicle 100 may include a communication unit 110, a control unit 120, a memory unit 130, an input and output unit 140a, and a positioning unit 140b.

The communication unit 110 may transmit and receive signals (e.g., data, control signals, etc.) with other vehicle external devices or base stations, etc. The control unit 120 may perform various operations by controlling elements of the vehicle 100. The control unit 120 may control the memory unit 130 and/or the communication unit 110 and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts included in the present disclosure. The memory unit 130 may store data/parameters/programs/codes/commands that support various functions of the vehicle 100. The input and output unit 140a may output the AR/VR object based on the information in the memory unit 130. The input and output unit 140a may include a HUD. The positioning unit 140b may obtain the position information of the vehicle 100. The position information may include absolute position information of the vehicle 100, position information in a traveling lane, acceleration information, position information with surrounding vehicles, and the like. The positioning unit 140b may include a GPS and various sensors.

In an example, the communication unit 110 of the vehicle 100 may receive map information, traffic information, and the like from an external server and store them in the memory unit 130. The positioning unit 140b may obtain vehicle position information through GPS and various sensors and store it in the memory unit 130. The control unit 120 may generate virtual objects based on map information, traffic information, vehicle position information, and the like, and the input and output unit 140a may indicate the generated virtual objects on windows in the vehicles 1410, 1420. In addition, the control unit 120 may determine whether the vehicle 100 is operating normally in the driving lane based on the vehicle position information. When the vehicle 100 is abnormally outside the driving lane, the control unit 120 may instruct a warning on the window of the vehicle through the input and output unit 140 a. In addition, the control unit 120 may transmit a warning message about abnormal driving to the surrounding vehicle through the communication unit 110. According to circumstances, the control unit 120 may transmit the position information of the vehicle and the information about the driving/vehicle problem to the relevant institutions through the communication unit 110.

The above-described embodiments are intended to combine elements and features of the present disclosure in a predetermined form. Each element or feature should be considered optional unless explicitly mentioned otherwise. Each element or feature can be implemented without being combined with other elements or features. Furthermore, embodiments of the present disclosure may include combining some elements and/or features. The order of operations described in embodiments of the present disclosure may be changed. Some elements or features of one embodiment may be included in or substituted for corresponding elements or features of other embodiments. It is clear that embodiments may include combining claims without explicit dependencies in the claims or may be included as new claims by modification after application.

It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof. The foregoing detailed description is, therefore, not to be taken in a limiting sense, and is intended to be illustrative in every respect. The scope of the invention should be determined by a fair interpretation of the accompanying claims and all changes that come within the meaning and range of equivalency of the disclosure are intended to be embraced therein.

The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in accordance with the methods of the various embodiments in a device or computer, as well as non-transitory computer-readable media that store such software or instructions, etc., and that can be executed in a device or computer. Commands that may be used to program a processing system that performs the features described in this disclosure may be stored in a storage medium or a computer readable storage medium, and the features described in this disclosure may be implemented by using a computer program product that includes such a storage medium. The storage medium may include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state storage devices, and it may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices located remotely from the processor. The memory, or alternatively, the non-volatile memory device in the memory, includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any one of a variety of machine-readable media to control the hardware of the processing system, and may be integrated into software and/or firmware that allows the processing system to interact with other mechanisms using results from embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.

Here, the wireless communication technology implemented in the wireless device 100, 200 of the present disclosure may include narrowband internet of things for low power communication and LTE, NR, and 6G. Here, for example, NB-IoT technology may be an example of LPWAN (low power wide area network) technology, may be implemented in standards such as LTE Cat NB1 and/or LTE Cat NB2, and is not limited to the above names. Additionally or alternatively, wireless communication techniques implemented in the wireless devices 100, 200 of the present disclosure may perform communications based on LTE-M techniques. Here, in an example, the LTE-M technology may be an example of LPWAN technology and may be referred to as various names such as eMTC (enhanced machine type communication) or the like. For example, LTE-M technology may implement 1) LTE CAT 0, 2) LTE CAT M1, 3) LTE CAT M2, 4) LTE non-BL (non-bandwidth limited), 5) LTE-MTC, 6) LTE machine type communication, and/or 7) LTE M, etc., in at least any of various standards including, but not limited to, the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless device 100, 200 of the present disclosure may include at least any one of ZigBee, bluetooth, and Low Power Wide Area Network (LPWAN) that allows for low power communication, and it is not limited to the above names. In an example, the ZigBee technology may generate PANs (personal area networks) related to small/low power digital communication based on various standards such as ieee802.15.4, and may be referred to by various names.

[ Industrial availability ]

The method proposed by the invention is mainly described by taking the application to 3GPP LTE/LTE-A and 5G systems as an example, but can also be applied to various wireless communication systems except for the 3GPP LTE/LTE-A and 5G systems.

Claims

1. A method of receiving a Physical Downlink Control Channel (PDCCH) in a wireless communication system, the method performed by a terminal comprising:

Receiving configuration information related to a control resource set (CORESET) from a base station, wherein the configuration information includes a plurality of Transmission Configuration Indicator (TCI) state candidates, and each of the plurality of TCI state candidates includes information for configuring a quasi co-location (QCL) relationship between one or more reference signals and one or more antenna ports of a demodulation reference signal (DMRS) of a PDCCH;

receiving a single Medium Access Control (MAC) Control Element (CE) from the base station for indicating two TCI states of the CORESET among the plurality of TCI state candidates; and

A first PDCCH in the CORESET is received from the base station,

Wherein, based on activation of the two TCI states by the single MAC CE for the CORESET, one or more antenna ports of the DMRS of the first PDCCH in the CORESET are quasi co-located (QCLed) with reference signals of the two TCI states, and

Wherein the MAC CE includes i) CORESET Identifier (ID) field, ii) a first TCI state ID field indicating one of the two TCI states applicable to the CORESET identified by the CORESET ID field, and iii) a second TCI state ID field indicating the other of the two TCI states applicable to the CORESET identified by the CORESET ID field.

2. The method according to claim 1,

Wherein the configuration information includes TCI state combination candidates configurable with a plurality of TCI state candidates for the CORESET,

Wherein the two TCI states are activated for the CORESET by the single MAC CE indicating a particular TCI state combination among the TCI state combination candidates.

3. The method according to claim 1,

Wherein based on the two TCI states configured for the CORESET, it is assumed that the first PDCCH is transmitted through a Single Frequency Network (SFN) based on the two TCI states.

4. The method according to claim 1,

Wherein channel estimation and/or channel compensation for the first PDCCH is performed based on each channel value corresponding to the reference signals of the two TCI states.

5. The method according to claim 1,

Wherein, based on repeated transmission of the first PDCCH in a plurality of transmission opportunities for the same Downlink Control Information (DCI),

Wherein each of the plurality of transmission opportunities corresponds to a different one of the two TCI states.

6. The method of claim 1, wherein the two TCI states are activated for the CORESET by the single MAC CE based on i) Single Frequency Network (SFN) operation for the first PDCCH and ii) one or more antenna ports of the DMRS of the first PDCCH in the CORESET are quasi-co-located (QCLed) with reference signals of the two TCI states.

7. A terminal for receiving a Physical Downlink Control Channel (PDCCH) in a wireless communication system, the terminal comprising:

at least one transceiver for transmitting and receiving radio signals; and

At least one processor for controlling the at least one transceiver,

Wherein the at least one processor is configured to:

A first PDCCH in the CORESET is received from the base station,

8. A non-transitory computer readable medium storing at least one instruction,

Wherein the at least one instruction executable by the at least one processor controls an apparatus for receiving a Physical Downlink Control Channel (PDCCH) to:

A first PDCCH in the CORESET is received from the base station,

9. A processing apparatus configured to control a terminal to receive a Physical Downlink Control Channel (PDCCH) in a wireless communication system, the processing apparatus comprising:

At least one processor; and

At least one computer memory operably connected to the at least one processor and storing instructions that, based on execution by the at least one processor, perform operations comprising:

A first PDCCH in the CORESET is received from the base station,

Wherein, based on activation of the two TCI states by the single MAC CE for CORESET, one or more antenna ports of the DMRS of the first PDCCH in the CORESET are quasi co-located (QCLed) with reference signals of the two TCI states, configuring a plurality of TCI states for the CORESET, and

10. A method of transmitting a Physical Downlink Control Channel (PDCCH) in a wireless communication system, the method performed by a base station comprising:

Transmitting configuration information related to a control resource set (CORESET) to a terminal, wherein the configuration information includes a plurality of Transmission Configuration Indicator (TCI) state candidates, and each of the plurality of TCI state candidates includes information for configuring a quasi co-location (QCL) relationship between one or more reference signals and one or more antenna ports of a demodulation reference signal (DMRS) of a PDCCH;

Transmitting a single Medium Access Control (MAC) Control Element (CE) to the terminal for indicating two TCI states of the CORESET among the plurality of TCI state candidates; and

The first PDCCH in CORESET is transmitted to the terminal,

11. The method of claim 10, wherein the two TCI states are activated for the CORESET by the single MAC CE based on i) Single Frequency Network (SFN) operation for the first PDCCH and ii) one or more antenna ports of the DMRS of the first PDCCH in the CORESET are quasi-co-located (QCLed) with reference signals of the two TCI states.

12. A base station for transmitting a Physical Downlink Control Channel (PDCCH) in a wireless communication system, the base station comprising:

at least one transceiver for transmitting and receiving radio signals; and

At least one processor for controlling the at least one transceiver,

Wherein the at least one processor is configured to:

The first PDCCH in CORESET is transmitted to the terminal,